Vulnerability Description
Starlet versions from 0.20 before 0.33 for Perl allow CPU exhaustion via regular expression backtracking when decoding chunked request bodies. A chunk-size line is matched as a run of hex digits, then .* and a CRLF. A run followed by a bare LF and then a CRLF can never match, and the engine retries the match once for each digit, so the time taken grows with the square of the run length. Nothing limits the length of the run, which can span several reads. A remote attacker can occupy a worker for about a minute of CPU time with one 128 KiB request, before the application is called.
Related Weaknesses (CWE)
References
- https://github.com/kazuho/Starlet/commit/229ea56b3b50028e2a644156317e8d0e7cf68a1
- https://metacpan.org/release/KAZUHO/Starlet-0.33/changes
FAQ
What is CVE-2026-115866?
CVE-2026-115866 is a documented vulnerability. Starlet versions from 0.20 before 0.33 for Perl allow CPU exhaustion via regular expression backtracking when decoding chunked request bodies. A chunk-size line is matched as a run of hex digits, the...
How severe is CVE-2026-115866?
CVSS scoring is not yet available for CVE-2026-115866. Check NVD for updates.
Is there a patch for CVE-2026-115866?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.