Skip to main content
VulnerabilityPublished

CVE-2026-126190: Soup Sieve · Polynomial-time denial of service in the descendant combinator

Affects flexgetSource GCVE Database

0
Compare
Authoritative record:CVE-2026-126190· High 7.5

Not known to be exploited · CVSS 7.5 High : upgrade to 3.22.11 soon.

Data as of 13 Nov 2026, 21:16 UTC

CVSS 3.1 base score
7.5High
How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none
CVSS scores by source
CNA (GitHub_M)CVSS 3.17.5
Patch
Available – fixed in 3.22.11
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 12 Nov 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.

What to do

Upgrade flexget to 3.22.11.

Affected software

ProductAffectedFixed in
Homebrewflexgetpkg:brew/flexgetOther threatsAffected
  • >=3.17.7 <3.22.11
Fixed in
  • 3.22.11

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix is available in Soup Sieve version 3.22.11 and later. Users should upgrade to this version or newer to eliminate the vulnerability. The fix introduces caching that reduces the matching time complexity to linear. If upgrading is not possible, users should minimize the use of descendant combinators in selectors applied to untrusted documents, limit the size and nesting depth of such documents, or run selection operations with time limits (e.g., in a separate worker process). The caching mechanism is enabled by default, and no code changes beyond upgrading are needed.

Description

CVE-2026-126190 is a denial of service vulnerability in Soup Sieve's handling of CSS selectors with descendant combinators. The matching algorithm exhibits polynomial time complexity relative to document nesting depth, causing excessive CPU usage on deeply nested documents. This affects applications that run such selectors on untrusted HTML or XML input. The issue is fixed in Soup Sieve version 3.22.11 and later.

References

Community reviews

Loading reviews…