CVE-2026-33894 — Forge has signature forgery in RSA-PKCS due to ASN.1 extra field

Description (CNA)

Forge (also called `node-forge`) is a native implementation of Transport Layer Security in JavaScript. Prior to version 1.4.0, RSASSA PKCS#1 v1.5 signature verification accepts forged signatures for low public exponent keys (e=3). Attackers can forge signatures by stuffing “garbage” bytes within the ASN structure in order to construct a signature that passes verification, enabling Bleichenbacher style forgery. This issue is similar to CVE-2022-24771, but adds bytes in an addition field within the ASN structure, rather than outside of it. Additionally, forge does not validate that signatures include a minimum of 8 bytes of padding as defined by the specification, providing attackers additional space to construct Bleichenbacher forgeries. Version 1.4.0 patches the issue.

Affected (CNA)

Vendor / product	Versions
digitalbazaar / forge	affected < 1.4.0

CWE

CWE-347, CWE-20

References

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.

redhat-SADP

A flaw was found in Forge (also called `node-forge`), a JavaScript implementation of Transport Layer Security. A remote attacker could exploit weaknesses in the RSASSA PKCS#1 v1.5 signature verification process. By crafting malicious signatures that include extra data within the ASN structure and do not meet padding requirements, an attacker can bypass signature validation. This allows for the creation of forged signatures that appear legitimate, potentially compromising the integrity and authenticity of communications.