facelessuser Soup Sieve up to 2.x CSS_ESCAPES soupsieve.compile escape output

CVSS Meta Temp Score
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CTI Interest Score
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6.3$0-$5k0.00+

Summaryinfo

A vulnerability was found in facelessuser Soup Sieve up to 2.x and classified as problematic. Affected by this issue is the function soupsieve.compile of the component CSS_ESCAPES/IDENTIFIER regular-expression subpatterns. Executing a manipulation can lead to escape output. This vulnerability is handled as CVE-2026-126191. The attack can be executed remotely. There is not any exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in facelessuser Soup Sieve up to 2.x. It has been declared as problematic. This vulnerability affects the function soupsieve.compile of the component CSS_ESCAPES/IDENTIFIER regular-expression subpatterns. The manipulation with an unknown input leads to a escape output vulnerability. The CWE definition for the vulnerability is CWE-116. The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved. As an impact it is known to affect availability. CVE summarizes:

Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 3.0, the CSS_ESCAPES and IDENTIFIER regular-expression subpatterns can backtrack exponentially on runs of ambiguous digit escapes in an attribute-name or tag position of an otherwise valid selector. The failure occurs during selector compilation through soupsieve.compile() or Beautiful Soup select() before SELECTOR_LIMIT is applied, so an application that accepts untrusted selector strings can have a worker stalled by a short input. This issue is fixed in version 3.0.

The advisory is available at github.com. This vulnerability was named CVE-2026-126191 since 11/10/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are known, but there is no available exploit.

Upgrading to version 3.0 eliminates this vulnerability.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.4
VulDB Meta Temp Score: 6.3

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.5
CNA Vector (GitHub_M): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Escape output
CWE: CWE-116 / CWE-74 / CWE-707
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Soup Sieve 3.0

Timelineinfo

11/10/2026 CVE reserved
11/12/2026 +2 days Advisory disclosed
11/12/2026 +0 days VulDB entry created
11/12/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: github.com
Status: Confirmed

CNA: GitHub_M
CVE: CVE-2026-126191 (🔒)

GCVE (CVE): GCVE-0-2026-126191
GCVE (VulDB): GCVE-100-436426

Entryinfo

Created: 11/12/2026 18:19
Changes: 11/12/2026 18:19 (65)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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