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8 vulnerabilities found for soupsieve by facelessuser
CVE-2026-86000 (GCVE-0-2026-86000)
Vulnerability from nvd – Published: 2026-09-17 15:21 – Updated: 2026-09-17 15:45
VLAI
EPSS
VEX
Title
Soup Sieve: Polynomial-time ReDoS (O(n²)) in the `IDENTIFIER` / `VALUE` selector sub-patterns
Summary
Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.9, the selector parser in src/soupsieve/css_parser.py defines IDENTIFIER with adjacent quantified groups over overlapping character classes, and VALUE embeds IDENTIFIER for attribute selectors. When an attacker-controlled selector contains a long identifier or unquoted attribute-value run followed by input that makes the overall match fail, the regular expression engine explores quadratically many splits between the overlapping groups. User-controlled selectors can reach this path through soupsieve.compile(), soupsieve.select(), or BeautifulSoup.select(), while applications using only hard-coded selectors are unaffected. The resulting CPU consumption can hold the Python GIL, exhaust application workers, and stall a service; successful plain identifier matches are linear, and the issue does not cause memory corruption or code execution. The issue is fixed in version 2.9.
Severity
5.3 (Medium)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-17 15:45 UTC
CWE
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/facelessuser/soupsieve/securit… | x_refsource_CONFIRM |
| https://github.com/facelessuser/soupsieve/commit/… | x_refsource_MISC |
| https://github.com/facelessuser/soupsieve/release… | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| facelessuser | soupsieve |
Affected:
< 2.9
|
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CVE-2026-85999 (GCVE-0-2026-85999)
Vulnerability from nvd – Published: 2026-09-17 15:23 – Updated: 2026-09-22 20:29
VLAI
EPSS
VEX
Title
Soup Sieve: Polynomial-time ReDoS (O(n²)) in the whitespace/comment trimming regex `RE_WS_END` (triggers on VALID selectors)
Summary
Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.9, selector_iter in src/soupsieve/css_parser.py trims the raw selector with RE_WS_END, an end-anchored WSC whitespace-and-comment expression used with search(), so the regular expression engine retries a greedy scan at every starting offset. An attacker-controlled valid selector containing a long internal whitespace run, or a selector containing a long CSS comment run followed by another token, causes quadratic CPU work before tokenization. User-controlled selectors can reach the path through soupsieve.compile() and BeautifulSoup.select(), while applications using only hard-coded selectors are unaffected. This root cause is separate from the IDENTIFIER and VALUE backtracking vulnerability because the cost occurs in RE_WS_END.search during trimming rather than token matching. The resulting CPU consumption can hold the Python GIL, exhaust workers, and stall a service without causing memory corruption or code execution. The issue is fixed in version 2.9.
Severity
5.3 (Medium)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-22 16:55 UTC
CWE
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/facelessuser/soupsieve/securit… | x_refsource_CONFIRM |
| https://github.com/facelessuser/soupsieve/commit/… | x_refsource_MISC |
| https://github.com/facelessuser/soupsieve/release… | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| facelessuser | soupsieve |
Affected:
< 2.9
|
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CVE-2026-49477 (GCVE-0-2026-49477)
Vulnerability from nvd – Published: 2026-07-14 20:51 – Updated: 2026-07-21 14:49
VLAI
EPSS
VEX
Title
Soup Sieve: Regular Expression Denial of Service (ReDoS) in soupsieve Selector Parser
Summary
Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.8.4, the CSS selector parser in soupsieve contains a regular expression vulnerable to catastrophic backtracking when processing an attribute selector with an unterminated quoted value in soupsieve/css_parser.py, allowing an attacker who can supply untrusted CSS selector strings to soupsieve.compile() or Beautiful Soup .select() / .select_one() to cause CPU exhaustion and denial of service. This issue is fixed in version 2.8.4.
Severity
7.5 (High)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-21 14:49 UTC
CWE
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/facelessuser/soupsieve/securit… | x_refsource_CONFIRM |
| https://github.com/facelessuser/soupsieve/commit/… | x_refsource_MISC |
| https://github.com/facelessuser/soupsieve/release… | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| facelessuser | soupsieve |
Affected:
< 2.8.4
|
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CVE-2026-49476 (GCVE-0-2026-49476)
Vulnerability from nvd – Published: 2026-07-14 20:53 – Updated: 2026-07-15 14:27
VLAI
EPSS
VEX
Title
Soup Sieve: Memory Exhaustion via Large Comma-Separated Selector Lists in soupsieve
Summary
Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.8.4, the CSS selector parser in soupsieve allocates unbounded memory when compiling large comma-separated selector lists, allowing an attacker who can supply a crafted selector string to soupsieve.compile() or Beautiful Soup .select() / .select_one() to allocate hundreds of megabytes of heap memory from a relatively small input and cause denial of service. This issue is fixed in version 2.8.4.
Severity
7.5 (High)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-15 14:26 UTC
CWE
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/facelessuser/soupsieve/securit… | x_refsource_CONFIRM |
| https://github.com/facelessuser/soupsieve/commit/… | x_refsource_MISC |
| https://github.com/facelessuser/soupsieve/release… | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| facelessuser | soupsieve |
Affected:
< 2.8.4
|
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CVE-2026-85999 (GCVE-0-2026-85999)
Vulnerability from cvelistv5 – Published: 2026-09-17 15:23 – Updated: 2026-09-22 20:29
VLAI
EPSS
VEX
Title
Soup Sieve: Polynomial-time ReDoS (O(n²)) in the whitespace/comment trimming regex `RE_WS_END` (triggers on VALID selectors)
Summary
Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.9, selector_iter in src/soupsieve/css_parser.py trims the raw selector with RE_WS_END, an end-anchored WSC whitespace-and-comment expression used with search(), so the regular expression engine retries a greedy scan at every starting offset. An attacker-controlled valid selector containing a long internal whitespace run, or a selector containing a long CSS comment run followed by another token, causes quadratic CPU work before tokenization. User-controlled selectors can reach the path through soupsieve.compile() and BeautifulSoup.select(), while applications using only hard-coded selectors are unaffected. This root cause is separate from the IDENTIFIER and VALUE backtracking vulnerability because the cost occurs in RE_WS_END.search during trimming rather than token matching. The resulting CPU consumption can hold the Python GIL, exhaust workers, and stall a service without causing memory corruption or code execution. The issue is fixed in version 2.9.
Severity
5.3 (Medium)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-22 16:55 UTC
CWE
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/facelessuser/soupsieve/securit… | x_refsource_CONFIRM |
| https://github.com/facelessuser/soupsieve/commit/… | x_refsource_MISC |
| https://github.com/facelessuser/soupsieve/release… | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| facelessuser | soupsieve |
Affected:
< 2.9
|
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CVE-2026-86000 (GCVE-0-2026-86000)
Vulnerability from cvelistv5 – Published: 2026-09-17 15:21 – Updated: 2026-09-17 15:45
VLAI
EPSS
VEX
Title
Soup Sieve: Polynomial-time ReDoS (O(n²)) in the `IDENTIFIER` / `VALUE` selector sub-patterns
Summary
Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.9, the selector parser in src/soupsieve/css_parser.py defines IDENTIFIER with adjacent quantified groups over overlapping character classes, and VALUE embeds IDENTIFIER for attribute selectors. When an attacker-controlled selector contains a long identifier or unquoted attribute-value run followed by input that makes the overall match fail, the regular expression engine explores quadratically many splits between the overlapping groups. User-controlled selectors can reach this path through soupsieve.compile(), soupsieve.select(), or BeautifulSoup.select(), while applications using only hard-coded selectors are unaffected. The resulting CPU consumption can hold the Python GIL, exhaust application workers, and stall a service; successful plain identifier matches are linear, and the issue does not cause memory corruption or code execution. The issue is fixed in version 2.9.
Severity
5.3 (Medium)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-17 15:45 UTC
CWE
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/facelessuser/soupsieve/securit… | x_refsource_CONFIRM |
| https://github.com/facelessuser/soupsieve/commit/… | x_refsource_MISC |
| https://github.com/facelessuser/soupsieve/release… | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| facelessuser | soupsieve |
Affected:
< 2.9
|
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CVE-2026-49476 (GCVE-0-2026-49476)
Vulnerability from cvelistv5 – Published: 2026-07-14 20:53 – Updated: 2026-07-15 14:27
VLAI
EPSS
VEX
Title
Soup Sieve: Memory Exhaustion via Large Comma-Separated Selector Lists in soupsieve
Summary
Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.8.4, the CSS selector parser in soupsieve allocates unbounded memory when compiling large comma-separated selector lists, allowing an attacker who can supply a crafted selector string to soupsieve.compile() or Beautiful Soup .select() / .select_one() to allocate hundreds of megabytes of heap memory from a relatively small input and cause denial of service. This issue is fixed in version 2.8.4.
Severity
7.5 (High)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-15 14:26 UTC
CWE
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/facelessuser/soupsieve/securit… | x_refsource_CONFIRM |
| https://github.com/facelessuser/soupsieve/commit/… | x_refsource_MISC |
| https://github.com/facelessuser/soupsieve/release… | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| facelessuser | soupsieve |
Affected:
< 2.8.4
|
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CVE-2026-49477 (GCVE-0-2026-49477)
Vulnerability from cvelistv5 – Published: 2026-07-14 20:51 – Updated: 2026-07-21 14:49
VLAI
EPSS
VEX
Title
Soup Sieve: Regular Expression Denial of Service (ReDoS) in soupsieve Selector Parser
Summary
Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.8.4, the CSS selector parser in soupsieve contains a regular expression vulnerable to catastrophic backtracking when processing an attribute selector with an unterminated quoted value in soupsieve/css_parser.py, allowing an attacker who can supply untrusted CSS selector strings to soupsieve.compile() or Beautiful Soup .select() / .select_one() to cause CPU exhaustion and denial of service. This issue is fixed in version 2.8.4.
Severity
7.5 (High)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-21 14:49 UTC
CWE
Assigner
References
3 references
| URL | Tags |
|---|---|
| https://github.com/facelessuser/soupsieve/securit… | x_refsource_CONFIRM |
| https://github.com/facelessuser/soupsieve/commit/… | x_refsource_MISC |
| https://github.com/facelessuser/soupsieve/release… | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| facelessuser | soupsieve |
Affected:
< 2.8.4
|
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"lang": "en",
"type": "CWE"
}
]
},
{
"descriptions": [
{
"cweId": "CWE-1333",
"description": "CWE-1333: Inefficient Regular Expression Complexity",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-07-14T20:51:29.369Z",
"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
"shortName": "GitHub_M"
},
"references": [
{
"name": "https://github.com/facelessuser/soupsieve/security/advisories/GHSA-836r-79rf-4m37",
"tags": [
"x_refsource_CONFIRM"
],
"url": "https://github.com/facelessuser/soupsieve/security/advisories/GHSA-836r-79rf-4m37"
},
{
"name": "https://github.com/facelessuser/soupsieve/commit/eb4397618709186c109400448c6043b728217dc3",
"tags": [
"x_refsource_MISC"
],
"url": "https://github.com/facelessuser/soupsieve/commit/eb4397618709186c109400448c6043b728217dc3"
},
{
"name": "https://github.com/facelessuser/soupsieve/releases/tag/2.8.4",
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],
"url": "https://github.com/facelessuser/soupsieve/releases/tag/2.8.4"
}
],
"source": {
"advisory": "GHSA-836r-79rf-4m37",
"discovery": "UNKNOWN"
},
"title": "Soup Sieve: Regular Expression Denial of Service (ReDoS) in soupsieve Selector Parser"
}
},
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"cveId": "CVE-2026-49477",
"datePublished": "2026-07-14T20:51:29.369Z",
"dateReserved": "2026-05-30T04:17:43.095Z",
"dateUpdated": "2026-07-21T14:49:40.914Z",
"state": "PUBLISHED"
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