Vulnerability Description
YAML::Syck versions before 1.38 for Perl has an out-of-bounds read. The base60 (sexagesimal) parsing code in perl_syck.h has a buffer underflow bug in both int#base60 and float#base60 handlers. When processing the leftmost segment of a colon-separated value (e.g., the 1 in 1:30:45), the inner while loop can decrement a pointer past the start of the string buffer: while ( colon >= ptr && *colon != ':' ) { colon--; } if ( *colon == ':' ) *colon = '\0'; // colon may be ptr-1 here When no colon is found (final/leftmost segment), colon becomes ptr-1, and the subsequent *colon dereference reads one byte before the allocated buffer.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/cpan-authors/YAML-Syck/commit/208a4d3bd1b5cdb4a791a6e3905bd6b
- https://github.com/cpan-authors/YAML-Syck/issues/132
- https://github.com/cpan-authors/YAML-Syck/pull/133
- https://metacpan.org/release/TODDR/YAML-Syck-1.38/changes
- http://www.openwall.com/lists/oss-security/2026/05/12/16
- https://github.com/cpan-authors/YAML-Syck/issues/132
FAQ
What is CVE-2026-5089?
CVE-2026-5089 is a vulnerability with a CVSS score of 7.3 (HIGH). YAML::Syck versions before 1.38 for Perl has an out-of-bounds read. The base60 (sexagesimal) parsing code in perl_syck.h has a buffer underflow bug in both int#base60 and float#base60 handlers. When...
How severe is CVE-2026-5089?
CVE-2026-5089 has been rated HIGH with a CVSS base score of 7.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-5089?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.