CVE-2026-4599 jsrsasign: Incomplete Comparison Allows DSA Private Key Recovery via Biased Nonce Generation
An attacker can recover private keys by exploiting biased DSA nonces caused by incorrect comparison logic in the jsrsasign library.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-4599?
CVE-2026-4599 is a critical vulnerability in jsrsasign, published on 23 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Versions of the package jsrsasign from 7.0.0 and before 11.1.1 are vulnerable to Incomplete Comparison with Missing Factors via the getRandomBigIntegerZeroToMax and getRandomBigIntegerMinToMax functions in src/crypto-1.1.js; an attacker can recover the private key by exploiting the incorrect compareTo checks that accept out-of-range candidates and thus bias DSA nonces during signature generation.
Which versions are affected by CVE-2026-4599?
2 open source packages ship an affected version, including jsrsasign. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
jsrsasign npm | From 7.0.0 | 11.1.1 |
jsrsasign npm | From 7.0.0 | 11.1.1 |
Products include Kjur Jsrsasign.
How do I fix CVE-2026-4599?
Upgrade jsrsasign to 11.1.1 or later.
Is CVE-2026-4599 being exploited?
There is no known exploitation of CVE-2026-4599 in the wild and no public exploit code.
Other vulnerabilities in jsrsasign
- CVE-2020-14967 RSA PKCS#1 decryption vulnerability with prepending zeros in jsrsasign
- CVE-2020-14968 RSA-PSS signature validation vulnerability by prepending zeros in jsrsasign
- CVE-2026-4601 jsrsasign: Missing cryptographic validation during DSA signing enables private key extraction
- CVE-2026-4600 jsrsasign: DSA signatures or X.509 certificates can be forged via DSA domain-parameter validation in KJUR.crypto.DSA.setPublic
- CVE-2021-30246 RSA signature validation vulnerability on maleable encoded message in jsrsasign
Sources
Also known as GHSA-5jx8-q4cp-rhh6.