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CVE-2026-4177

Estado: ModificadaCrítica (9.1)—

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.

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

YAML::Syck remoto sin autenticación (AV:N,PR:N,UI:N). Heap buffer overflow permite ejecutar código arbitrario (T1059) o causar DoS (T1499.004). Impacto crítico con escalada potencial de privilegios (T1068).

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Privileged Account ManagementFilter Network TrafficVulnerability ScanningRestrict Web-Based ContentNetwork SegmentationLimit Software Installation

Tecnologías afectadas (1)

Toddr — Yaml\

CWE

Referencias

JSON original (NVD)

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      "value": "YAML::Syck versions through 1.36 for Perl has several potential security vulnerabilities including a high-severity heap buffer overflow in the YAML emitter.\n\nThe heap overflow occurs when class names exceed the initial 512-byte allocation.\n\nThe base64 decoder could read past the buffer end on trailing newlines.\n\nstrtok mutated n->type_id in place, corrupting shared node data.\n\nA 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."
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    }
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    {
      "nodes": [
        {
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