Vulnerability · Published Sep 3, 2026 · Assigned by VulnCheck

CVE-2026-85393node-forge through 1.4.0 RSA PKCS#1 v1.5 Signature Forgery via Nested DigestAlgorithm Padding

High 7.5

In plain English

A high-severity security flaw in forge from digitalbazaar. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 16% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.2%top 83.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

node-forge through 1.4.0 fails to validate element count in nested DigestAlgorithm sequences during RSA PKCS#1 v1.5 signature verification. Attackers can embed garbage bytes inside the DigestAlgorithm sequence to forge valid signatures for arbitrary messages using low-exponent RSA keys. This is an incomplete fix for CVE-2026-33894.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Ubuntu:22.04:LTS	node-node-forge	no fix listed	UBUNTU-CVE-2026-85393
npm	node-forge	no fix listed	GHSA-86w9-cpqp-85rv
npm	node-forge	1.4.0	GHSA-ppp5-5v6c-4jwp

Affected products (as reported)

Vendor	Product	Versions
digitalbazaar	forge	0 – through 1.4.0

Weakness: CWE-347 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

References

GitHub Issue #1149 issue-tracking
https://github.com/digitalbazaar/forge product
https://github.com/digitalbazaar/forge/blob/v1.4.0/lib/rsa.js technical-description
https://github.com/digitalbazaar/forge/blob/v1.4.0/lib/asn1.js technical-description
GitHub Security Advisory (GHSA-ppp5-5v6c-4jwp) related
VulnCheck Advisory: node-forge through 1.4.0 RSA PKCS#1 v1.5 Signature Forgery via Nested DigestAlgorithm Padding third-party-advisory