CVE-2026-4602

Name: CVE-2026-4602
Creator: NVD / NIST
Published: 2026-03-23T06:16:22.07+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.7/10EPSS 0.40%

Last modified Jun 25, 2026

CVE-2026-4602 is a high-severity vulnerability rated 7.7/10 on the CVSS scale. 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.. EPSS estimates a 0.40% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS 4.0

7.7/10

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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.40%

31.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-681

Affected Software

Vendor	Product	Versions
Kjur	Jsrsasign	< 11.1.1

References

https://gist.github.com/Kr0emer/7ecd2be7d17419e4677315ef3758faf5Exploit, Mitigation, Third Party Advisory
https://github.com/kjur/jsrsasign/commit/5ea1c32bb2aa894b4bd29849839afe4f98728195Patch
https://github.com/kjur/jsrsasign/pull/650Issue Tracking
https://security.snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-15812274
https://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15371175Third Party Advisory

Timeline

Published: Mar 23, 2026
Last Modified: Jun 25, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2026-4602?

How severe is CVE-2026-4602?

CVE-2026-4602 has a CVSS score of 7.7/10 (HIGH severity). The EPSS model estimates a 0.40% probability of exploitation in the next 30 days.

How do I fix CVE-2026-4602?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-4602?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST