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.
References7
- github.com/advisories/GHSA-ppp5-5v6c-4jwp
- github.com/digitalbazaar/forge
- github.com/digitalbazaar/forge/blob/v1.4.0/lib/asn1.js
- github.com/digitalbazaar/forge/blob/v1.4.0/lib/rsa.js
- github.com/digitalbazaar/forge/issues/1149
- www.vulncheck.com/advisories/node-forge-through-1.4.0-rsa-pkcs-…
- github.com/advisories/GHSA-ppp5-5v6c-4jwp
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - CVSS 4.0
-
8.7
HIGH
Score source: CNA
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 16 · as of 3 November 2026
- CWE
- CWE-347
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.