Skip to main content
No exploitation reportedFix available

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

No exploitation reported by the sources we read.

  • Published2026-10-30
  • WeaknessCWE-1333

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2026-10-3012:45CVE publishedCNA

Versions per branch

Products declared by the CNA1 product

As CPANSec, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-10-30

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • starletUbuntu:26.10all versions · no fixed version listed
  • starletUbuntu:26.04:LTSall versions · no fixed version listed
  • starletUbuntu:24.04:LTSall versions · no fixed version listed
  • starletUbuntu:22.04:LTSall versions · no fixed version listed
  • starletUbuntu:20.04:LTSall versions · no fixed version listed
  • starletUbuntu:18.04:LTSall versions · no fixed version listed
  • starletUbuntu:16.04:LTSall versions · no fixed version listed
  • starletDebian:14all versions · fixed in 0.33-1

2 more package ranges on OSV.dev

Vendor advisories

  • CVE-2026-115866 Red Hat Product Security

    perl-starlet: Starlet: Denial of Service via regular expression backtracking

Full record on NVD

Fix

No fix published by the sources we read yet. NVD record

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof of concept
Metasploit modules
none listed
Metasploit Framework

Sources

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2026-10-30
Last Modified
2026-11-06
NVD status
Deferred
GitHub Advisory
GHSA-8jc4-2m4j-6vf8

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.

Is CVE-2026-115866 actively exploited?

Active exploitation of CVE-2026-115866 has not been confirmed. Its EPSS score was 0.2% on 2026-11-05, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-115866?

CVE-2026-115866 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Running perl-starlet? Hear about its next vulnerability

Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».

Get alerts for this productCISA KEV additions, November 2026Search CVEs

No credit card required · No monthly cap on website lookups · 250 API requests/month

Go further

Related vulnerabilities

Same product first, then the same vendor advisory and the same publication week.

Back to CVE Database

Sources for this record