CVE-2026-115866

Unknown

Last modified

CVE-2026-115866 is a vulnerability of currently unknown severity. 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.

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.

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
——>= 0.20, < 0.33

References

Timeline

Published
Last Modified
Status
Deferred

Frequently Asked Questions

What is CVE-2026-115866?
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.
How severe is CVE-2026-115866?
Severity scoring for CVE-2026-115866 is pending analysis.
How do I fix CVE-2026-115866?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST