CVE-2026-33894 Forge has signature forgery in RSA-PKCS due to ASN.1 extra field
Attackers can forge RSA-PKCS#1 v1.5 signatures in node-forge by exploiting ASN.1 parsing flaws, bypassing signature verification.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-33894?
CVE-2026-33894 is a high-severity vulnerability in digitalbazaar forge, published on 27 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2026-33894?
It affects 1 product.
Products include Digitalbazaar Forge.
How do I fix CVE-2026-33894?
Upgrade to a fixed version.
Is CVE-2026-33894 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33894 exists.
Other vulnerabilities in digitalbazaar forge
- CVE-2020-7720 Prototype Pollution
- CVE-2025-66031 node-forge ASN.1 Unbounded Recursion
- CVE-2025-12816 CVE-2025-12816
- CVE-2026-33891 Forge has Denial of Service via Infinite Loop in BigInteger.modInverse() with Zero Input
- CVE-2026-33895 Forge has signature forgery in Ed25519 due to missing S > L check
Sources
Also known as CLEANSTART-2026-NK73842, CLEANSTART-2026-ZI53736, MINI-4fx3-46r7-9rwx, MINI-5rxg-2777-xw37, MINI-5w8g-7hj3-x7pf, MINI-646m-fh43-83qm and 17 more.