VulnerabilityModified

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.

HIGH 7.7EPSS 0.50%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.50%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 4.0: 7.7 HIGHCVSS: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/M
EPSS: 0.50% probability · 42th percentile
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-681
Affected: kjur/jsrsasign
Source: report@snyk.io

EPSS trend

EPSS 0.5% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.