CVE-2026-4598 jsrsasign is vulnerable to DoS through Infinite Loop when processing zero or negative inputs
An attacker can cause a permanent process hang in the jsrsasign library by supplying zero or negative inputs to the BigInteger.modInverse function.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-4598?
CVE-2026-4598 is a high-severity denial of service 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 before 11.1.1 are vulnerable to Infinite loop via the bnModInverse function in ext/jsbn2.js when the BigInteger.modInverse implementation receives zero or negative inputs, allowing an attacker to hang the process permanently by supplying such crafted values (e.g., modInverse(0, m) or modInverse(-1, m)).
Which versions are affected by CVE-2026-4598?
2 open source packages ship an affected version, including jsrsasign. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
jsrsasign npm | All versions | 11.1.1 |
jsrsasign npm | All versions | 11.1.1 |
Products include Kjur Jsrsasign.
How do I fix CVE-2026-4598?
Upgrade jsrsasign to 11.1.1 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-4598 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-4598 exists.
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-2026-4599 jsrsasign: Incomplete Comparison Allows DSA Private Key Recovery via Biased Nonce Generation
- CVE-2026-4600 jsrsasign: DSA signatures or X.509 certificates can be forged via DSA domain-parameter validation in KJUR.crypto.DSA.setPublic
Sources
Also known as GHSA-8g7p-jf3g-gxcp.