Read the docs
TI-2026-04444 Aliases CVE-2026-5089GHSA-jcwf-qrr5-xwq3

YAML::Syck versions before 1.38 for Perl has an out-of-bounds read

Priority HIGH 71CWE-124Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
Low · Low · Low
Fix status
Partial Red Hat: 2 without a fix

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00404 34th percentileScored 2026-11-07
Fix Partial YAML::Syck (TODDR): 1.38Red Hat: 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
TODDRYAML::Syckbefore 1.381.38Patch availableCNA
  • YAML::Syck VendorTODDR Affected before 1.38 Fixed in 1.38 Patch available CNA

Remediation

  • Fix · CNA YAML::Syck (TODDR) Fixed in 1.38

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 8AffectedNo fix yet: Fix deferred

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-5089
  2. 2026-10-03 Alias added: GHSA-jcwf-qrr5-xwq3

References

Patch 1

Other 3

  • TI-2006-06994 Heap-based buffer overflow in TODDR XML::Parser CVSS 3.1CRITICAL 9.8
  • TI-2006-06993 Heap-based buffer overflow in TODDR XML::Parser CVSS 3.1CRITICAL 9.8
  • TI-2026-41065 Out-of-bounds read in TODDR YAML::Syck CVSS 3.1CRITICAL 9.1
  • TI-2026-03625 Heap-based buffer overflow in TODDR YAML::Syck CVSS 3.1CRITICAL 9.1
  • TI-2026-41067 Out-of-bounds read in TODDR YAML::Syck CVSS 3.1HIGH 7.7
  • TI-2026-41066 Use after free in TODDR YAML::Syck CVSS 3.1HIGH 7.8
See all 8 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences