GHSA-4642-5MCJ-2RQW
Vulnerability from github – Published: 2026-10-30 23:02 – Updated: 2026-10-30 23:02Summary
asn1.oidToDer() did not range-check the first two arcs of an OID string, so an OID such as 0.42.840.113549.1.1.1 or 4294977127.18.840.113549.1.1.1 was encoded as the DER of a different OID (here rsaEncryption, 1.2.840.113549.1.1.1). This is an incomplete fix of CVE-2025-66030. Fixed in node-forge 1.4.1.
Details
X.690 section 8.19 encodes the first two arcs of an OID as one subidentifier, 40 * arc1 + arc2, where the first arc is 0, 1 or 2 and the second arc is at most 39 when the first is 0 or 1. asn1.oidToDer() in lib/asn1.js computed that value with no range check and wrote it with putByte(), which keeps only the low 16 bits. Out-of-range first arcs therefore produced the encoding of a different OID: 0.42.840.113549.1.1.1 gives 40 * 0 + 42 = 42 and 4294977127.18.840.113549.1.1.1 wraps to 42, both the first byte of rsaEncryption. The fix for CVE-2025-66030 (GHSA-65ch-62r8-g69g, node-forge 1.3.2) added a 32-bit check for the later arcs only.
A related encoding bug made valid OIDs with a first subidentifier above 127 (2.48 and higher, e.g. 2.999) encode and decode incorrectly, because the first subidentifier was always written and read as a single byte.
The fix rejects out-of-range first arcs and encodes and decodes the first subidentifier in base 128 like the others (the latter from public PR #1148).
Patches
Fixed in node-forge 1.4.1. asn1.oidToDer() throws for OIDs with out-of-range first arcs, and the first subidentifier is encoded and decoded correctly.
Workarounds
Validate OID strings from untrusted input before passing them to node-forge: the first arc must be 0, 1 or 2, and the second arc at most 39 when the first arc is 0 or 1.
Credits
Reported by wzc. The first subidentifier encoding fix is from PR #1148 by @spokodev.
Proof of concept
var forge = require('node-forge');
var der = forge.asn1.oidToDer('0.42.840.113549.1.1.1');
console.log(der.toHex()); // 2a864886f70d010101
console.log(forge.asn1.derToOid(der)); // 1.2.840.113549.1.1.1
On 1.4.0 the out-of-range OID string encodes to exactly the DER of rsaEncryption (the same happens with 4294977127.18.840.113549.1.1.1). On 1.4.1 oidToDer() throws "Invalid OID; the first two arcs are out of range.".
Regression tests are in tests/unit/asn1.js ("should reject OIDs with out of range first arcs").
Impact
Applications that accept OID strings from untrusted input, check or authorize them as strings, and then encode them with node-forge (for example when building certificates, CSRs or other ASN.1 structures from user-supplied extension or attribute OIDs) can be made to emit a different, trusted OID than the one that was checked. Parsing DER is not affected. There is no confidentiality or availability impact.
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 1.4.0"
},
"package": {
"ecosystem": "npm",
"name": "node-forge"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.4.1"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2026-118775"
],
"database_specific": {
"cwe_ids": [
"CWE-190"
],
"github_reviewed": true,
"github_reviewed_at": "2026-10-30T23:02:40Z",
"nvd_published_at": "2026-10-29T19:17:20Z",
"severity": "LOW"
},
"details": "### Summary\n\n`asn1.oidToDer()` did not range-check the first two arcs of an OID string, so an OID such as `0.42.840.113549.1.1.1` or `4294977127.18.840.113549.1.1.1` was encoded as the DER of a different OID (here rsaEncryption, `1.2.840.113549.1.1.1`). This is an incomplete fix of CVE-2025-66030. Fixed in node-forge 1.4.1.\n\n### Details\n\nX.690 section 8.19 encodes the first two arcs of an OID as one subidentifier, `40 * arc1 + arc2`, where the first arc is 0, 1 or 2 and the second arc is at most 39 when the first is 0 or 1. `asn1.oidToDer()` in `lib/asn1.js` computed that value with no range check and wrote it with `putByte()`, which keeps only the low 16 bits. Out-of-range first arcs therefore produced the encoding of a different OID: `0.42.840.113549.1.1.1` gives `40 * 0 + 42 = 42` and `4294977127.18.840.113549.1.1.1` wraps to 42, both the first byte of rsaEncryption. The fix for CVE-2025-66030 (GHSA-65ch-62r8-g69g, node-forge 1.3.2) added a 32-bit check for the later arcs only.\n\nA related encoding bug made valid OIDs with a first subidentifier above 127 (`2.48` and higher, e.g. `2.999`) encode and decode incorrectly, because the first subidentifier was always written and read as a single byte.\n\nThe fix rejects out-of-range first arcs and encodes and decodes the first subidentifier in base 128 like the others (the latter from public PR #1148).\n\n### Patches\nFixed in node-forge 1.4.1. `asn1.oidToDer()` throws for OIDs with out-of-range first arcs, and the first subidentifier is encoded and decoded correctly.\n\n### Workarounds\nValidate OID strings from untrusted input before passing them to node-forge: the first arc must be 0, 1 or 2, and the second arc at most 39 when the first arc is 0 or 1.\n\n### Credits\nReported by wzc. The first subidentifier encoding fix is from PR #1148 by @spokodev.\n\n### Proof of concept\n\n var forge = require(\u0027node-forge\u0027);\n var der = forge.asn1.oidToDer(\u00270.42.840.113549.1.1.1\u0027);\n console.log(der.toHex()); // 2a864886f70d010101\n console.log(forge.asn1.derToOid(der)); // 1.2.840.113549.1.1.1\n\nOn 1.4.0 the out-of-range OID string encodes to exactly the DER of rsaEncryption (the same happens with `4294977127.18.840.113549.1.1.1`). On 1.4.1 `oidToDer()` throws \"Invalid OID; the first two arcs are out of range.\".\n\nRegression tests are in tests/unit/asn1.js (\"should reject OIDs with out of range first arcs\").\n\n### Impact\n\nApplications that accept OID strings from untrusted input, check or authorize them as strings, and then encode them with node-forge (for example when building certificates, CSRs or other ASN.1 structures from user-supplied extension or attribute OIDs) can be made to emit a different, trusted OID than the one that was checked. Parsing DER is not affected. There is no confidentiality or availability impact.",
"id": "GHSA-4642-5mcj-2rqw",
"modified": "2026-10-30T23:02:40Z",
"published": "2026-10-30T23:02:40Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/digitalbazaar/forge/security/advisories/GHSA-4642-5mcj-2rqw"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-118775"
},
{
"type": "WEB",
"url": "https://github.com/digitalbazaar/forge/commit/e56a3dde8e4e63bae566bb32546eeaf92f515e1e"
},
{
"type": "PACKAGE",
"url": "https://github.com/digitalbazaar/forge"
},
{
"type": "WEB",
"url": "https://github.com/digitalbazaar/forge/releases/tag/v1.4.1"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N",
"type": "CVSS_V3"
}
],
"summary": "Forge: ASN.1 OID first arc truncation in asn1.oidToDer"
}
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