Vulnerability · Published Sep 29, 2026 · Assigned by VulnCheck
CVE-2026-103043anchorme through 3.0.8 Regular Expression Denial of Service
High 7.5
In plain English
A high-severity regular-expression denial of service in anchorme from alexcorvi. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 48% of all known vulnerabilities).
Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.6%top 51.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
anchorme through 3.0.8 contains a regular expression denial of service vulnerability in the IPv6 host extraction regex due to catastrophic backtracking. Attackers can supply specially crafted input strings with repeated patterns to cause exponential regex engine backtracking, blocking the Node.js event loop and denying service to other requests.
Affected products (as reported)
Weakness: CWE-1333 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- https://gist.github.com/mmadersbacher/46050b4224eb979431986cdef1dd2ad3 third-party-advisory
- https://github.com/alexcorvi/anchorme.js/blob/f3ae9850baa344f27b46bb149e9b891831d273b1/src/index.ts#L109 technical-description
- https://www.npmjs.com/package/anchorme product
- https://github.com/alexcorvi/anchorme.js product
- VulnCheck Advisory: anchorme through 3.0.8 Regular Expression Denial of Service third-party-advisory
- https://gist.github.com/R3tro16/92948206e9893a3739b91746439384ab technical-description, exploit