CVE-2026-57076

YAML::Syck versions before 1.47 for Perl allow a heap use-after-free via an anchor name reused as an anchors-table key in syck_hdlr_add_anchor. In the bundled libsyck an anchor name allocated by syck_strndup is stored both as node->anchor, freed when the node is freed, and as the key in the parser's anchors table. Freeing the node frees the shared key, and a later anchor redefinition makes st_delete compare against the freed key, so st_strcmp reads freed heap memory. Anchors are a standard YAML feature and need no special flags, so this is reached on the default Load path. Any caller that runs Load or LoadFile on an untrusted document that redefines an anchor reaches the read of freed memory.

CVSS v3 7.8 HIGH

7.8^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.8 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/toddr/YAML-Syck/commit/44c90a109ec3215ee7ce747bd11209835e123d8b.patch
https://metacpan.org/release/TODDR/YAML-Syck-1.47/changes
http://www.openwall.com/lists/oss-security/2026/07/17/3

Configurations

No configuration.

History

17 Jul 2026, 14:17

Type	Values Removed	Values Added
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 7.8

17 Jul 2026, 04:16

Type	Values Removed	Values Added
References		() http://www.openwall.com/lists/oss-security/2026/07/17/3 -

16 Jul 2026, 22:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-07-16 22:17

Updated : 2026-07-17 15:07

NVD link : CVE-2026-57076

Mitre link : CVE-2026-57076

CVE.ORG link : CVE-2026-57076

JSON object : View

Products Affected

No product.

CWE

CWE-416

Use After Free

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