CVE-2026-59870
Vulnerability Summary
Timeline
Description
js-yaml is a JavaScript YAML parser and dumper. From 5.0.0 before 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. This issue is fixed in version 5.2.1.
CVSS Metrics
- v3.1•MEDIUM•Score: 5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- v3.1•HIGH•Score: 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Trends
Current EPSS score: 0.64%• Percentile: 49%
Techniques & Countermeasures
- CWE-407•Inefficient Algorithmic Complexity
An algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached.
- CWE-770•Allocation of Resources Without Limits or Throttling
The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.
Affected Systems
- chainguard•renovate
< 44.3.3-r0 | < 44.3.2-r0
- wolfi•renovate
< 44.3.3-r0 | < 44.3.2-r0
- nodeca•js-yaml
≥ 5.0.0, < 5.2.1
- Npm•js-yaml
≥ 5.0.0, < 5.2.1
References (6)
- https://github.com/nodeca/js-yaml/security/advisories/GHSA-724g-mxrg-4qvm
- https://github.com/nodeca/js-yaml/commit/39f3211a2f01b3c6982710cf21434ab7060acefe
- https://github.com/nodeca/js-yaml/releases/tag/5.2.1
- https://nvd.nist.gov/vuln/detail/CVE-2026-59870
- https://github.com/nodeca/js-yaml
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59870.json