Out-of-bounds read in YAML-Syck - CVE-2025-11683

Vulnerability identifier: #VU117839

CSH Severity: Medium

CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2025-11683

CWE-ID: CWE-125

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to a boundary condition in token.c. A remote attacker can trigger an out-of-bounds read error and read contents of memory on the system.

YAML-Syck
Fedora
Ubuntu
Anolis OS
libyaml-syck-perl (Ubuntu package)
perl-YAML-Syck
perl-YAML-Syck-doc

Install updates from vendor's website.

YAML-Syck - update to 1.36
libyaml-syck-perl (Ubuntu package) - addressed in versions 1.29-1ubuntu0.16.04.1~esm1, 1.29-1ubuntu0.18.04.1~esm1, 1.31-1ubuntu0.1~esm1, 1.34-1ubuntu0.1~esm1, 1.34-2ubuntu0.24.04.1~esm1, 1.34-2ubuntu0.25.04.1, 1.34-3ubuntu0.1
perl-YAML-Syck - update to 1.36-1
perl-YAML-Syck-doc - update to 1.36-1
perl-YAML-Syck - addressed in versions 1.36-1.el9, 1.36-1.el10_2, 1.36-1.fc41, 1.36-1.fc42

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

• Information disclosure in YAML::Syck
• Ubuntu update for libyaml-syck-perl
• Fedora 42 update for perl-YAML-Syck
• Fedora EPEL 10.2 update for perl-YAML-Syck
• Fedora EPEL 9 update for perl-YAML-Syck
• Fedora 41 update for perl-YAML-Syck
• Anolis OS update for perl-YAML-Syck