# CVE-2026-5089

## Summary

- **CVE ID:** CVE-2026-5089
- **Severity:** HIGH
- **CVSS Score:** 7.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L)
- **CWE:** CWE-124
- **Published:** May 12, 2026
- **Last Modified:** May 14, 2026

## 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.

## Affected Products

- TODDR — YAML::Syck (0)

## References

- [CNA](https://metacpan.org/release/TODDR/YAML-Syck-1.38/changes)
- [CNA](https://github.com/cpan-authors/YAML-Syck/issues/132)
- [CNA](https://github.com/cpan-authors/YAML-Syck/pull/133)
- [CNA](https://github.com/cpan-authors/YAML-Syck/commit/208a4d3bd1b5cdb4a791a6e3905bd6bd45e9d005.patch)
- [CVE](http://www.openwall.com/lists/oss-security/2026/05/12/16)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.33%
- **EPSS Percentile:** 26.2

---
_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-12._