CPANSA-Starlet-2026-115866: Starlet vulnerability
| Publisher | giterlizzi | Document category | csaf_security_advisory |
|---|---|---|---|
| Initial release date | 2026-10-30T00:00:00 | Engine | CSAF Perl Toolkit 0.26 |
| Current release date | 2026-10-30T00:00:00 | Build Date | |
| Current version | 1 | Status | final |
| CVSS v3.1 Base Score | Severity | ||
| Original language | Language | en | |
| Also referred to | |||
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.
Vulnerabilities
CVE-2026-115866
Vulnerability DescriptionStarlet 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 | CWE-1333 : Inefficient Regular Expression Complexity |
|---|
Product status
Known affected
| Product | Score | ||||
|---|---|---|---|---|---|
| Starlet greater than or equal 0.20 and less than 0.33 |
|
Fixed
- Starlet greater than or equal 0.33
giterlizzi
Namespace: https://github.com/giterlizzi/
gdt@cpan.org
References
- CPANSA-Starlet-2026-115866 JSON self
https://raw.githubusercontent.com/giterlizzi/perl-CPANSA-CSAF/develop/csaf/white/2026/cpansa-starlet-2026-115866.json - https://github.com/kazuho/Starlet/commit/229ea56b3b50028e2a644156317e8d0e7cf68a1f.patch external
https://github.com/kazuho/Starlet/commit/229ea56b3b50028e2a644156317e8d0e7cf68a1f.patch - https://metacpan.org/release/KAZUHO/Starlet-0.33/changes external
https://metacpan.org/release/KAZUHO/Starlet-0.33/changes - CVE-2026-115866 (NVD) external
https://nvd.nist.gov/vuln/detail/CVE-2026-115866
Revision history
| Version | Date of the revision | Summary of the revision |
|---|---|---|
| 1 | Fri Oct 30 00:00:00 2026 | First release |
Sharing rules
TLP:WHITE
For the TLP version see: https://www.first.org/tlp/