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TI-2026-03625 Aliases CVE-2026-4177GHSA-72r6-p2x3-g9gj

Heap-based buffer overflow in TODDR YAML::Syck

Priority MEDIUM 46CWE-122Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
High · None · High
Fix status
Partial Red Hat: 2 fixed, 1 without a fix

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

Summary

YAML::Syck versions through 1.36 for Perl has several potential security vulnerabilities including a high-severity heap buffer overflow in the YAML emitter. The heap overflow occurs when class names exceed the initial 512-byte allocation. The base64 decoder could read past the buffer end on trailing newlines. strtok mutated n->type_id in place, corrupting shared node data. A memory leak occurred in syck_hdlr_add_anchor when a node already had an anchor. The incoming anchor string 'a' was leaked on early return.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00455 39th percentileScored 2026-11-07
Fix Partial Red Hat: 2 advisoriesRed Hat: 2 fixed, 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
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::Syckup to 1.36—No fix listedCNA
  • YAML::Syck VendorTODDR Affected up to 1.36 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:toddr:yaml\:\:syck:*:*:*:*:*:perl:*:* syckVulnerableTODDR
  • cpe:2.3:a:toddr:yaml\:\:syck:*:*:*:*:*:perl:*:* Versions syck Vulnerable ·TODDR

Remediation

Red Hat 2 advisories

  • RHSA-2026:8311 Released 2026-04-15 · Red Hat rating Important
    perl-YAML-Syck security update
    • Red Hat Enterprise Linux Server Optional (v. 7 ELS) perl-YAML-Syck-1.27-3.el7_9.1
  • RHSA-2026:6470 Released 2026-04-02 · Red Hat rating Important
    perl-YAML-Syck security update
    • Red Hat Enterprise Linux CRB (v. 8) perl-YAML-Syck-1.30-6.el8_10

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2026:6470
Red Hat Enterprise Linux Server Optional (v. 7 ELS)Fixed RHSA-2026:8311

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-4177
  2. 2026-10-03 Alias added: GHSA-72r6-p2x3-g9gj

References

Patch 1

Advisory 1

Other 1

  • TI-2025-10713 Memory corruption in TODDR YAML::Syck CVSS 3.1MEDIUM 6.5

Sources

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