VulnerabilityAnalyzed
CVE-2026-59869
js-yaml is a JavaScript YAML parser and dumper.
HIGH 7.5EPSS 0.54%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.54%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.54% probability · 44th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-407
- Affected
- nodeca/js-yaml
- Source
- security-advisories@github.com
References
- https://github.com/nodeca/js-yaml/commit/24f13e79ee1343a7e30bd6f6c9d9cdbf0ac9b2b7Patch
- https://github.com/nodeca/js-yaml/commit/59423c6f8cdc78742ac00e25a4dd39ef16b702e4Patch
- https://github.com/nodeca/js-yaml/releases/tag/3.15.0Release Notes
- https://github.com/nodeca/js-yaml/releases/tag/4.3.0Release Notes
- https://github.com/nodeca/js-yaml/security/advisories/GHSA-52cp-r559-cp3mExploit, Vendor Advisory
- https://github.com/nodeca/js-yaml/security/advisories/GHSA-52cp-r559-cp3mExploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.