CVE-2025-11683

YAML::Syck versions before 1.36 for Perl has missing null-terminators which causes out-of-bounds read and potential information disclosure Missing null terminators in token.c leads to but-of-bounds read which allows adjacent variable to be read The issue is seen with complex YAML files with a hash of all keys and empty values.  There is no indication that the issue leads to accessing memory outside that allocated to the module.

CVSS 3.1

6.5CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS

0.3% chance of exploitation in the next 30 days; higher than 23% of CVEs (scores of 2026-10-25)

CWE

CWE-119

Published

2025-10-16

Modified

2026-10-08

Record from

the NVD, synced 2026-10-19

Affected

• toddr:yaml\

References

• https://github.com/cpan-authors/YAML-Syck/pull/65
• https://metacpan.org/dist/YAML-Syck/changes

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