CVE-2026-59870

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.

• CWE-407
• CWE-770

• https://github.com/nodeca/js-yaml/commit/22a8071ef032117bc6249c330b240ac3aa2d3ded
• https://github.com/nodeca/js-yaml/commit/39f3211a2f01b3c6982710cf21434ab7060acefePatch
• https://github.com/nodeca/js-yaml/commit/c3cc4b0bb9ddb9af2dd9b61e0d56f5ce7983cd4a
• https://github.com/nodeca/js-yaml/releases/tag/3.15.1
• https://github.com/nodeca/js-yaml/releases/tag/4.3.1
• https://github.com/nodeca/js-yaml/releases/tag/5.2.1Release Notes
• https://github.com/nodeca/js-yaml/security/advisories/GHSA-724g-mxrg-4qvmExploit, Vendor Advisory
• https://github.com/nodeca/js-yaml/security/advisories/GHSA-724g-mxrg-4qvmExploit, Vendor Advisory

Published

Jul 8, 2026

Last Modified

Oct 25, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2026-59865Kiota is an OpenAPI based HTTP Client code generator. Prior …9.3
• CVE-2026-59866Kiota is an OpenAPI based HTTP Client code generator. Prior …9.3
• CVE-2026-59867Kiota is an OpenAPI based HTTP Client code generator. Prior …7.1
• CVE-2026-59868js-yaml is a JavaScript YAML parser and dumper. From 5.0.0 b…7.5
• CVE-2026-59869js-yaml is a JavaScript YAML parser and dumper. From 3.0.0 b…7.5
• CVE-2026-5987A security vulnerability has been detected in Sanluan Public…4.7
• CVE-2026-59871node-tar is a tar archive manipulation library for Node.js. …7.5
• CVE-2026-59873node-tar is a tar archive manipulation library for Node.js. …7.5
• CVE-2026-59874node-tar is a tar archive manipulation library for Node.js. …7.5
• CVE-2026-59875node-tar is a tar archive manipulation library for Node.js. …5.3
• CVE-2026-59876protobufjs compiles protobuf definitions into JavaScript (JS…4.8
• CVE-2026-59877protobufjs compiles protobuf definitions into JavaScript (JS…7.5