CVE-2025-11683

EUVD-2025-34701
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
6.5 MEDIUM
ADJACENT_NETWORK
LOW
NONE
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Affected Products (NVD)
VendorProductVersion
toddryaml\
𝑥
< 1.36
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
libyaml-syck-perl
bookworm
1.34-2+deb12u1
fixed
bookworm (security)
1.34-2+deb12u2
fixed
bullseye
vulnerable
bullseye (security)
1.34-1+deb11u1
fixed
forky
1.36-2
fixed
sid
1.36-2
fixed
trixie
1.34-2+deb13u1
fixed
trixie (security)
1.34-2+deb13u2
fixed
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
libyaml-syck-perl
bionic
Fixed 1.29-1ubuntu0.18.04.1~esm1
released
focal
Fixed 1.31-1ubuntu0.1~esm1
released
jammy
Fixed 1.34-1ubuntu0.1~esm1
released
noble
Fixed 1.34-2ubuntu0.24.04.1~esm1
released
plucky
Fixed 1.34-2ubuntu0.25.04.1
released
questing
Fixed 1.34-3ubuntu0.1
released
xenial
Fixed 1.29-1ubuntu0.16.04.1~esm1
released