---
title: "CVE-2026-4599: jsrsasign: Incomplete Comparison Allows DSA Private Key Recovery via Biased Nonce Generation"
url: https://erroneo.us/security/cve/CVE-2026-4599/
description: "CVE-2026-4599 (jsrsasign (npm)): Versions of the package jsrsasign from 7.0.0 and before 11.1.1 are vulnerable to Incomplete Comparison with Missing Factors…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-03-23
date_modified: 2026-09-10
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-4599"
kev: false
cvss: 9.3
epss: 0.0081
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-4599: jsrsasign: Incomplete Comparison Allows DSA Private Key Recovery via Biased Nonce Generation

**Signal:** Critical and remotely reachable. No known exploitation yet, but it is network-reachable without credentials. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 0.8% , percentile 56: FIRST’s model estimates a 0.8% chance of exploitation activity in the next 30 days, higher than 56% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Only applies if your dependency tree includes jsrsasign (npm) >= 7.0.0, < 11.1.1, fixed in 11.1.1 . Check your lockfile, including transitive dependencies.

## What it is

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.

## Affected packages

- npm `jsrsasign` >= 7.0.0, < 11.1.1 → fixed: 11.1.1

## Affected products (CVE record)

- n/a jsrsasign: 7.0.0 < 11.1.1
- n/a org.webjars.npm:jsrsasign: 8.0.12 < *

## Severity

- snyk CVSS 4.0: 9.3 `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`
- snyk CVSS 3.1: 9.1 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`
- redhat-SADP CVSS 3.1: 9.1 `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`
- GitHub CVSS 4.0: 9.3 `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable yes , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.81% probability of exploitation activity in the next 30 days; percentile 56.

## Sources

- [access.redhat.com](https://access.redhat.com/errata/RHSA-2026:19409)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2026:19410)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2026:6912)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2026:6720)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2026:6568)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2026:19375)
- [access.redhat.com](https://access.redhat.com/errata/RHSA-2026:6926)
- [GitHub Advisory GHSA-5jx8-q4cp-rhh6](https://github.com/advisories/GHSA-5jx8-q4cp-rhh6)
- [CVE.org record CVE-2026-4599](https://www.cve.org/CVERecord?id=CVE-2026-4599)
- [NVD entry CVE-2026-4599](https://nvd.nist.gov/vuln/detail/CVE-2026-4599)
- [security.snyk.io](https://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15370939)
- [security.snyk.io](https://security.snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-15812264)
- [gist.github.com](https://gist.github.com/Kr0emer/081681818b51605c91945126d74b4f20)
- [github.com](https://github.com/kjur/jsrsasign/pull/647)
- [github.com](https://github.com/kjur/jsrsasign/commit/ee4b013478366cb16cea9a4bdfb218b6077f83b1)
- [access.redhat.com](https://access.redhat.com/security/cve/CVE-2026-4599)
- [RHBZ#2450207](https://bugzilla.redhat.com/show_bug.cgi?id=2450207)
- [security.access.redhat.com](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4599.json)

---
Source page: https://erroneo.us/security/cve/CVE-2026-4599/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt