CVE-2026-4602
HIGH7.5EPSS 0.08%jsrsasign: Negative Exponent Handling Leads to Signature Verification Bypass
Published: 3/23/2026Modified: 3/30/2026
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 (1)
- npm/jsrsasignfrom 0, < 11.1.1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P |
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
References (6)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-4602
- PATCHhttps://github.com/kjur/jsrsasign
- WEBhttps://gist.github.com/Kr0emer/7ecd2be7d17419e4677315ef3758faf5
- WEBhttps://github.com/kjur/jsrsasign/commit/5ea1c32bb2aa894b4bd29849839afe4f98728195
- WEBhttps://github.com/kjur/jsrsasign/pull/650
- WEBhttps://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15371175