js-yaml quadratic-complexity denial of service via YAML11_SCHEMA !!omap parsing (nodeca js-yaml)

CVE-2026-59870
HIGH 7.5

At a glance

Source
NVD
EPSS
EPSS 0.74 % · percentile 54 ()
State
PUBLISHED
Published
Updated
Assigner
GitHub_M
NVD status
Modified

Description

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.

Weaknesses (CWE)

  • CWE-407 — Inefficient Algorithmic Complexity
  • CWE-770 — Allocation of Resources Without Limits or Throttling

References

Scores

VersionScoreVectorScored by
CVSS 3.1HIGH 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HGitHub_M
CVSS 3.1HIGH 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HNVD · security-advisories@github.com (Secondary)
CVSS 3.1HIGH 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HNVD · nvd@nist.gov (Primary)

Advisories

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
nodeca · js-yamlaffected >= 5.0.0, < 5.2.1 ; affected >= 3.0.0, < 3.15.1 ; affected >= 4.0.0, < 4.3.1

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD