CVE-2026-33895
This class of signature malleability has been exploited in practice to bypass authentication and authorization logic (see CVE-2026-25793, CVE-2022-35961).
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.54%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 0.54% probability · 44th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-347
- Affected
- digitalbazaar/forge
- Source
- security-advisories@github.com
References
- https://datatracker.ietf.org/doc/html/rfc8032#section-8.4Third Party Advisory
- https://github.com/digitalbazaar/forge/commit/bdecf11571c9f1a487cc0fe72fe78ff6dfa96b85Patch
- https://github.com/digitalbazaar/forge/security/advisories/GHSA-q67f-28xg-22rwVendor Advisory
- https://access.redhat.com/errata/RHSA-2026:13826
- https://access.redhat.com/errata/RHSA-2026:24761
- https://access.redhat.com/errata/RHSA-2026:34342
- https://access.redhat.com/errata/RHSA-2026:9742
- https://access.redhat.com/security/cve/CVE-2026-33895
- https://bugzilla.redhat.com/show_bug.cgi?id=2452457
- https://github.com/digitalbazaar/forge/security/advisories/GHSA-q67f-28xg-22rwVendor Advisory
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33895.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.