Vulnerability · Published Mar 23, 2026 · Assigned by snyk
CVE-2026-4602
High 7.5
In plain English
A high-severity security flaw in jsrsasign. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 43% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.5%top 57.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
Versions of the package jsrsasign before 11.1.1 are vulnerable to Incorrect Conversion between Numeric Types due to handling negative exponents in ext/jsbn2.js. An attacker can force the computation of incorrect modular inverses and break signature verification by calling modPow with a negative exponent.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | jsrsasign | 11.1.1 | GHSA-8qwj-4jxw-m8jw |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| n/a | jsrsasign | 0 – before 11.1.1 |
| n/a | org.webjars.npm:jsrsasign | 0 – before * |
Weakness: CWE-681 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P
References
- https://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15371175
- https://security.snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-15812274
- https://gist.github.com/Kr0emer/7ecd2be7d17419e4677315ef3758faf5
- https://github.com/kjur/jsrsasign/pull/650
- https://github.com/kjur/jsrsasign/commit/5ea1c32bb2aa894b4bd29849839afe4f98728195
- https://access.redhat.com/security/cve/CVE-2026-4602 vdb-entry, x_refsource_REDHAT
- RHBZ#2450206 issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4602.json x_sadp-csaf-vex
- https://access.redhat.com/errata/RHSA-2026:19409 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:19410 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:6912 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:6720 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:6568 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:19375 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:6926 vendor-advisory, x_refsource_REDHAT