Is there a public exploit for CVE-2026-126189?

No public exploit for CVE-2026-126189 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-126189?

CVE-2026-126189 scores CVSS 5.3 (v3.1), rated medium.

What does CVE-2026-126189 affect?

CVE-2026-126189 affects facelessuser soupsieve.

5.3 Medium

Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4.

CVE-2026-126189

Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 4.0.1, Soup Sieve repeatedly searches descendant subtrees for each candidate evaluated by :has() and repeatedly reevaluates a parent containing :has(> ...) for each child, causing quadratic matching on deeply nested or wide attacker-influenced HTML or XML. Applications using ordinary fixed selectors through select(), selectone(), or Beautiful Soup CSS APIs against untrusted documents can have a worker occupied for seconds or minutes, while applications that process only trusted documents are not affected. Selectors compiled with NOCACHE continue to use the old uncached behavior. This issue is fixed in version 4.0.1.

Assessment

CVSS: 5.3 (v3.1)
Severity: Medium
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 12 November 2026
Last updated: 12 November 2026
Affected: facelessuser · soupsieve
Assigner: GitHub_M

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

At the source

EUVD (ENISA)

References

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