CVE-2026-84375: fallo de gravedad alta en nodeca js-yaml
js-yaml: maxTotalMergeKeys does not limit CPU use for empty merge sources
Publicada el · Actualizada el
Aviso por correo cuando entre en el KEV, tenga PoC pública o suba de nota.
21Vexday Risk Score
Sin señal de explotación. Ningún artefacto público de explotación conocido hasta ahora.
ssvc Trackcvss 7.5epss 0.5%
js-yaml is a JavaScript YAML parser and dumper. From 3.0.0 until 3.15.2, 4.3.2, and 5.4.1, maxTotalMergeKeys in lib/js-yaml/loader.js and lib/loader.js does not count empty mapping sources while processing the merge key <<. An attacker can alias a large sequence of empty mappings into many merge targets, causing O(N * K) processing while totalMergeKeys remains unchanged and the configured resource limit is never reached. A relatively small YAML document can therefore cause prolonged CPU consumption in applications that parse untrusted YAML, and merge processing is enabled by default on these release lines. In v3 & v4, merge is enabled by default so the severity score is higher. This issue is fixed in versions 3.15.2, 4.3.2, and 5.4.1.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Productos afectados
nodeca · js-yamlCVEs relacionadas — nodeca js-yaml
En el mismo producto, de las más peligrosas a las menos.
CVE-2026-59870HIGHjs-yaml quadratic-complexity denial of service via YAML11_SCHEMA !!omap parsingEPSS 0.7%CVE-2026-59868MEDIUMjs-yaml: YAML merge-key chains can force quadratic CPU consumptionEPSS 0.6%CVE-2026-59869HIGHjs-yaml: YAML merge-key chains can force quadratic CPU consumptionEPSS 0.6%CVE-2026-73643HIGHjs-yaml: Exponential parsing time in the flow collections leads to denial of serviceEPSS 0.5%CVE-2025-64718MEDIUMjs-yaml has prototype pollution in merge (<<)EPSS 0.4%CVE-2026-53550MEDIUMjs-yaml: Quadratic-complexity DoS in merge key handling via repeated aliasesEPSS 0.4%
Referencias
https://github.com/nodeca/js-yaml/commit/3485bc06ff8a0251505f44a00414d90df2466639https://github.com/nodeca/js-yaml/commit/6a8e05f9a485188ed730ac81e81ae221352ef480https://github.com/nodeca/js-yaml/commit/d90b6612a5a84385bdcb556c44578eac76dc0f6bhttps://github.com/nodeca/js-yaml/pull/797https://github.com/nodeca/js-yaml/releases/tag/3.15.2https://github.com/nodeca/js-yaml/releases/tag/4.3.2https://github.com/nodeca/js-yaml/releases/tag/5.4.1https://github.com/nodeca/js-yaml/security/advisories/GHSA-2883-xcg3-v3hh