CVE-2026-4177

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2026-4177
YAML::Syck versions through 1.36 for Perl has several potential security vulnerabilities including a high-severity heap buffer overflow in the YAML emitter. The heap overflow occurs when class names exceed the initial 512-byte allocation. The base64 decoder could read past the buffer end on trailing newlines. strtok mutated n->type_id in place, corrupting shared node data. A memory leak occurred in syck_hdlr_add_anchor when a node already had an anchor. The incoming anchor string 'a' was leaked on early return.

9.1 /10

CVSS v3 : CRITICAL

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 5.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://github.com/cpan-authors/YAML-Syck/commit/e8844a31c8cf0052914b198fc784ed4e6b8ae69e.patch Patch
https://metacpan.org/release/TODDR/YAML-Syck-1.37_01/changes#L21 Release Notes
http://www.openwall.com/lists/oss-security/2026/03/16/6 Mailing List Third Party Advisory
Configurations

Configuration 1 (hide)

cpe:2.3:a:toddr:yaml\:\:syck:*:*:*:*:*:perl:*:*
History

23 Mar 2026, 18:17

Type Values Removed Values Added
References () https://github.com/cpan-authors/YAML-Syck/commit/e8844a31c8cf0052914b198fc784ed4e6b8ae69e.patch - () https://github.com/cpan-authors/YAML-Syck/commit/e8844a31c8cf0052914b198fc784ed4e6b8ae69e.patch - Patch
References () https://metacpan.org/release/TODDR/YAML-Syck-1.37_01/changes#L21 - () https://metacpan.org/release/TODDR/YAML-Syck-1.37_01/changes#L21 - Release Notes
References () http://www.openwall.com/lists/oss-security/2026/03/16/6 - () http://www.openwall.com/lists/oss-security/2026/03/16/6 - Mailing List, Third Party Advisory
First Time Toddr yaml\
Toddr
CPE cpe:2.3:a:toddr:yaml\:\:syck:*:*:*:*:*:perl:*:*
Summary
  • (es) Las versiones de YAML::Syck hasta la 1.36 para Perl tienen varias vulnerabilidades de seguridad potenciales, incluyendo un desbordamiento de búfer de montículo de alta gravedad en el emisor YAML. El desbordamiento de montículo ocurre cuando los nombres de clase exceden la asignación inicial de 512 bytes. El decodificador base64 podría leer más allá del final del búfer en saltos de línea finales. strtok mutó n->type_id in situ, corrompiendo datos de nodo compartidos. Se produjo una fuga de memoria en syck_hdlr_add_anchor cuando un nodo ya tenía un ancla. La cadena de ancla entrante 'a' se filtró en el retorno anticipado.

17 Mar 2026, 14:20

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 9.1

17 Mar 2026, 02:16

Type Values Removed Values Added
References
  • () http://www.openwall.com/lists/oss-security/2026/03/16/6 -

16 Mar 2026, 23:16

Type Values Removed Values Added
New CVE
Information

Published : 2026-03-16 23:16

Updated : 2026-03-23 18:17

NVD link : CVE-2026-4177

Mitre link : CVE-2026-4177

CVE.ORG link : CVE-2026-4177

JSON object : View

Products Affected

toddr

  • yaml\
CWE
CWE-122

Heap-based Buffer Overflow