CVE-2026-33895

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

State
Published
Severity
7.5 High
Published
Mar 27, 2026
Updated
Sep 4, 2026
Reserved
Mar 24, 2026

Read the record on cve.org

Description

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.

Scores

CVSSScoreVectorSource
3.17.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:NGitHub_M
3.17.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:Nredhat-SADP

Weaknesses

  • CWE-347 Improper Verification of Cryptographic Signature

Affected Products

ProductVersions
forgedigitalbazaar
  • < 1.4.0Affected

References

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