CVE-2026-33895 PUBLISHED

Forge has signature forgery in Ed25519 due to missing S > L check

Assigner: GitHub_M
Reserved: 24.03.2026 Published: 27.03.2026 Updated: 27.03.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CVSS Score: 7.5

Product Status

Vendor digitalbazaar
Product forge
Versions
  • Version < 1.4.0 is affected

References

Problem Types

  • CWE-347: Improper Verification of Cryptographic Signature CWE