CVE catalog
CVE-2026-49477
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 backtracki
- Severity
- High · CVSS 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.64% · Oct 25, 2026
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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | soupsieve | sid | 2.8.4-1 | fixed |
| Debian | soupsieve | forky | 2.8.4-1 | fixed |
| Debian | soupsieve | trixie | 2.7-1 | vulnerable |
| Debian | soupsieve | bookworm | 2.3.2-1 | vulnerable |
| Cpe | soupsieve | Not reported | Not reported | vulnerable |
| PyPI | soupsieve | Not reported | 2.8.4 | fixed |
| Cpe | soup_sieve | Not reported | 2.8.4 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | soupsieve | source | sid | 2.8.4-1 | not yet assigned | Not reported | Not reported |
| Debian | soupsieve | source | forky | 2.8.4-1 | not yet assigned | Not reported | Not reported |
| Debian | soupsieve | source | trixie | (unfixed) | not yet assigned | Not reported | Not reported |
| Debian | soupsieve | source | bookworm | (unfixed) | not yet assigned | Not reported | Not reported |
| PyPI | soupsieve | PyPI | Not reported | 2.8.4 | Not reported | GHSA-836R-79RF-4M37 | Not reported |
| Cpe | soup_sieve | cpe | Not reported | 2.8.4 | Not reported | NVD-CVE-2026-49477 | Not reported |
Notes
[trixie] soupsieve: Minor issue [bookworm] soupsieve: Minor issue
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [python3-soupsieve]Affected
Source package: [soupsieve]
Details (2)
2.3.2-1· all · bookwormAffected
nvd · soupsieve · debian · bookworm; nvd · soupsieve · debian · 12
2.3.2-1· all · bookwormAffected
nvd · soupsieve · debian · bookworm; nvd · soupsieve · debian · 12
[Debian 13 (Trixie)]
- [python3-soupsieve]Affected
Source package: [soupsieve]
Details (2)
2.7-1· all · trixieAffected
nvd · soupsieve · debian · 13
2.7-1· all · trixieAffected
nvd · soupsieve · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/suse-su-2026_22660-1.json]
- [https://github.com/facelessuser/soupsieve/commit/eb4397618709186c109400448c6043b728217dc3]
- [https://github.com/facelessuser/soupsieve/releases/tag/2.8.4]
- [https://github.com/facelessuser/soupsieve/security/advisories/GHSA-836r-79rf-4m37]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-49477]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-49477]
- [https://osv.dev/vulnerability/GHSA-836r-79rf-4m37]
- [https://security-tracker.debian.org/tracker/CVE-2026-49477]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-49477.json]
[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]