CVE-2026-59870

EUVD-2026-42300
js-yaml is a JavaScript YAML parser and dumper. Prior to 3.15.1, 4.3.1, and 5.2.1, YAML11_SCHEMA support for the !!omap tag in src/tag/sequence/omap.ts uses omapTag.addItem() to perform a linear duplicate-key scan on every insertion, causing O(n^2) CPU consumption when yaml.load() parses a crafted ordered-map document. In v3 and v4, !!omap is active and exploitable by default. v5 doesn't use !!omap by default, and the chances of activating it are very low.This issue is fixed in 3.15.1, 4.3.1, and 5.2.1.
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: 49.16%
Affected Products (NVD)
VendorProductVersion
nodecajs-yaml
5.0.0 ≤
𝑥
< 5.2.1
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
node-js-yaml
bookworm
4.1.0+dfsg+~4.0.5-7
fixed
forky
4.3.2+~4.0.9-1
fixed
sid
4.3.2+~4.0.9-1
fixed
trixie
4.1.0+dfsg+~4.0.5-7
fixed
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