CVE-2026-13713 TODDR CVE debrief

Who should care

Users of YAML::Syck versions before 1.47 for Perl, operators, platforms, vulnerability-management teams, and security teams should review and apply patches to prevent potential denial of service attacks. Affected product deployments should be identified and owners assigned for follow-up.

Technical summary

YAML::Syck versions before 1.47 for Perl allow a use-after-free and double-free via an anchor node freed while still on the parser value stack. In the bundled libsyck, when an anchor name is redefined or removed, syck_hdlr_add_anchor and syck_hdlr_remove_anchor free the node stored under that name with syck_free_node. That node can still be live on the parser's value stack, so syck_hdlr_add_node reaches it again and frees it a second time. This vulnerability can be triggered by a 7-byte document that redefines an anchor, causing the interpreter to abort.

Defensive priority

High

Recommended defensive actions

• Review and apply patches for YAML::Syck versions before 1.47 for Perl
• Implement compensating controls to prevent potential denial of service attacks
• Monitor for and respond to potential exploitation attempts
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed
• Check relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

The CVE record was published on 2026-07-16T22:16:59.640Z and has not been modified since then. The NVD entry is currently Received. Evidence is limited to CVE and NVD details. Defenders should verify affected product deployments, review official advisories, and plan vendor-supported updates or mitigations.

Official resources