Vulnerability · CVE-2026-4602
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.
Published Mar 23, 2026 · catalog updated Sep 10, 2026 · Versions of the package
Check if you run it
No confirmed exploitation is on record for CVE-2026-4602. EPSS is 0.88%. Act only if a listed version of Versions of the package is installed.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (Versions of the package).
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- High7.7
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.88%
- Remediation
- Advisory link
- Affected products
- cpe kjur/jsrsasign
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.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe kjur/jsrsasignversion unspecified
How to fix CVE-2026-4602
Recommended remediation
A patch or advisory reference is linked. Open the original publisher for availability by product version.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-4602. EPSS is 0.88%. Act only if a listed version of Versions of the package is installed.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-681. EPSS 0.88%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Mar 23, 2026 · NIST NVD
Detected
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.
Sep 10, 2026 · NIST NVD
Updated
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.
Sources
- CVE.orgVulnerability recordCVE-2026-4602
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-4602
30-day exploitation probability 0.9%
first.org - NIST NVDVulnerability recordCVE-2026-4602
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
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.