CVE-2026-33895

HIGH

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

Title source: cna
STIX 2.1

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

CVSS v3 7.5
EPSS 0.0004
EPSS Percentile 12.1%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact partial

Details

CWE
CWE-347
Status published
Products (3)
digitalbazaar/forge < 1.3.3
digitalbazaar/forge < 1.4.0
npm/node-forge 0 - 1.4.0npm
Published Mar 27, 2026
Tracked Since Mar 29, 2026