7.7
HIGH CVSS 4.0
CVE-2026-4602
Apache jsrsasign Integer Overflow
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.

INFO

Published Date :

March 23, 2026, 6:16 a.m.

Last Modified :

March 23, 2026, 6:16 a.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-4602 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH [email protected]
CVSS 4.0 HIGH [email protected]
Solution
Update jsrsasign to version 11.1.1 or later to fix modular inverse calculation.
  • Update jsrsasign package to version 11.1.1 or newer.
  • Verify modular inverse calculations with negative exponents.
  • Implement input validation for exponent values.
  • Review cryptographic implementation details.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-4602.

URL Resource
https://gist.github.com/Kr0emer/7ecd2be7d17419e4677315ef3758faf5
https://github.com/kjur/jsrsasign/commit/5ea1c32bb2aa894b4bd29849839afe4f98728195
https://github.com/kjur/jsrsasign/pull/650
https://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15371175
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-4602 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-4602 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-4602 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-4602 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by [email protected]

    Mar. 23, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V4.0 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
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
    Added CWE CWE-681
    Added Reference https://gist.github.com/Kr0emer/7ecd2be7d17419e4677315ef3758faf5
    Added Reference https://github.com/kjur/jsrsasign/commit/5ea1c32bb2aa894b4bd29849839afe4f98728195
    Added Reference https://github.com/kjur/jsrsasign/pull/650
    Added Reference https://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15371175
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.