facelessuser soupsieve up to 2.8.3 CSS selector parser soupsieve/css_parser.py compile attribute incorrect regex

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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5.1$0-$5k0.67

Summaryinfo

A vulnerability described as problematic has been identified in facelessuser soupsieve up to 2.8.3. This vulnerability affects the function compile of the file soupsieve/css_parser.py of the component CSS selector parser. Such manipulation of the argument attribute leads to incorrect regex. This vulnerability is listed as CVE-2026-49477. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in facelessuser soupsieve up to 2.8.3. Affected by this issue is the function compile of the file soupsieve/css_parser.py of the component CSS selector parser. The manipulation of the argument attribute with an unknown input leads to a incorrect regex vulnerability. Using CWE to declare the problem leads to CWE-185. The product specifies a regular expression in a way that causes data to be improperly matched or compared. Impacted is availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-49477 since 05/30/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Technical details are known, but there is no available exploit.

Upgrading to version 2.8.4 eliminates this vulnerability.

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Productinfo

Vendor

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.1

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

CVSSv2info

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

Exploitinginfo

Class: Incorrect regex
CWE: CWE-185 / CWE-697
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: no mitigation known
Status: 🔍

0-Day Time: 🔒

Upgrade: soupsieve 2.8.4

Timelineinfo

05/30/2026 CVE reserved
07/15/2026 +46 days Advisory disclosed
07/15/2026 +0 days VulDB entry created
07/15/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-49477 (🔒)
GCVE (CVE): GCVE-0-2026-49477
GCVE (VulDB): GCVE-100-379118

Entryinfo

Created: 07/15/2026 02:39
Changes: 07/15/2026 02:39 (56)
Complete: 🔍
Cache ID: 216::103

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