CVE-2026-33895
Forge has signature forgery in Ed25519 due to missing S > L check
Forge (also called `node-forge`) is a native implementation of Transport Layer Security in JavaScript. Prior to version 1.4.0, Ed25519 signature verification accepts forged non-canonical signatures where the scalar S is not reduced modulo the group order (`S >= L`). A valid signature and its `S + L` variant both verify in forge, while Node.js `crypto.verify` (OpenSSL-backed) rejects the `S + L` variant, as defined by the specification. This class of signature malleability has been exploited in practice to bypass authentication and authorization logic (see CVE-2026-25793, CVE-2022-35961). Applications relying on signature uniqueness (i.e., dedup by signature bytes, replay tracking, signed-object canonicalization checks) may be bypassed. Version 1.4.0 patches the issue.
- Affected
- digitalbazaar · forge
- CVSS v3.1 CNA
- 7.5 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - EPSS
- 0.47% chance of exploitation in the next 30 days, 40th percentile
- Published
- 2026-03-27
- Updated
- 2026-09-04
Proof-of-concept exploits (1)
Security advisories
- digitalbazaar/forge/security/advisories/GHSA-q67f-28xg-22rw
- https://datatracker.ietf.org/doc/html/rfc8032#section-8.4
- digitalbazaar/forge/commit/bdecf11571c9f1a487cc0fe72fe78ff6dfa96b85