node-forge is a JavaScript implementations of network transports, cryptography, ciphers, PKI, message digests, and various utilities.
Affected versions of this package are vulnerable to Improper Verification of Cryptographic Signature in rsa.js, whose DigestInfo validation checks the outer element count (obj.value.length !== 2) but never verifies the element count of the inner DigestAlgorithm SEQUENCE, so the ASN.1 parser accepts extra children that are ignored during digest extraction. An attacker can forge a signature that verifies as valid for an arbitrary message, without the private key, by fixing the target digest at the block boundaries and filling roughly 314 garbage bytes inside the DigestAlgorithm structure to absorb the mathematical residue. This only affects verification against RSA keys with a low public exponent such as e=3, and although _parseAllDigestBytes defaults to true and rejects trailing garbage, it does not detect this interior padding.
Note: This is a bypass of the fix for the vulnerability described in CVE-2026-33894 and, as of this publication, has not been acknowledged by project maintainers.
Remediation
A fix was pushed into the master branch but not yet published.