Instituto Nacional de ciberseguridad. Sección Incibe
Instituto Nacional de Ciberseguridad. Sección INCIBE-CERT

CVE-2026-73643

Gravedad CVSS v3.1:
ALTA
Tipo:
No Disponible / Otro tipo
Fecha de publicación:
13/08/2026
Última modificación:
14/08/2026

Descripción

*** Pendiente de traducción *** js-yaml is a JavaScript YAML parser and dumper. From 5.0.0 until 5.2.2, parsing a small YAML document can take exponential time when an application calls load() or loadAll() on untrusted input. In src/parser/parser.ts, readFlowCollection uses restoreState and calls parseNode a second time when a flow-sequence entry is recognized as a key: value pair. If the key is a nested flow sequence of the same shape, every level is parsed twice, causing O(2^n) work and allowing an input under 200 bytes to keep one CPU busy for minutes, block the Node.js event loop, and stall the process. No anchors, aliases, merges, tags, or nondefault options are required. This issue is fixed in version 5.2.2.