CVE-2026-59869

EUVD-2026-42301
js-yaml is a JavaScript YAML parser and dumper. From 3.0.0 before 3.15.0 and from 4.0.0 before 4.3.0, js-yaml can spend quadratic CPU time parsing a document whose size grows only linearly when a chain of mappings uses merge keys where each mapping merges the previous one. This issue is fixed in versions 3.15.0 and 4.3.0.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
7.5 HIGH
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: 43.47%
Affected Products (NVD)
VendorProductVersion
nodecajs-yaml
3.0.0 ≤
𝑥
< 3.15.0
nodecajs-yaml
4.0.0 ≤
𝑥
< 4.3.0
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
node-js-yaml
bookworm
postponed
bullseye
postponed
forky
vulnerable
sid
4.2.0+~4.0.9-2
fixed
trixie
no-dsa
Ubuntu logo
Ubuntu Releases
Ubuntu Product
Codename
node-js-yaml
bionic
needs-triage
focal
needs-triage
jammy
needs-triage
noble
needs-triage
questing
ignored
resolute
needs-triage
Common Weakness Enumeration
Vulnerability Media Exposure
References
https://github.com/nodeca/js-yaml/commit/24f13e79ee1343a7e30bd6f6c9d9cdbf0ac9b2b7
https://github.com/nodeca/js-yaml/commit/59423c6f8cdc78742ac00e25a4dd39ef16b702e4
https://github.com/nodeca/js-yaml/releases/tag/3.15.0
https://github.com/nodeca/js-yaml/releases/tag/4.3.0
https://github.com/nodeca/js-yaml/security/advisories/GHSA-52cp-r559-cp3m
https://github.com/nodeca/js-yaml/security/advisories/GHSA-52cp-r559-cp3m