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CVE-2026-13713 Detail

Description

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. On a normal build the 48-byte node chunk is freed twice and the interpreter aborts. Anchors need no special flags, so this is reached on the default Load path, and a 7-byte document that redefines an anchor triggers it. Any caller that runs Load or LoadFile on an untrusted document that redefines an anchor mid-parse crashes the interpreter, a denial of service.


Metrics

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CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

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URL Source(s) Tag(s)
CVE
CPANSec
CPANSec

Weakness Enumeration

CWE-ID CWE Name Source
CWE-415 Double Free CPANSec  
CWE-416 Use After Free CPANSec  

Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-13713
NVD Published Date:
07/16/2026
NVD Last Modified:
07/17/2026
Source:
CPANSec