jsrsasign: Negative Exponent Handling Leads to Signature Verification Bypass

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.

Recommendation

Update the jsrsasign package to the latest compatible version. Followings are version details:

• Affected version(s): < 11.1.1
• Patched version(s): 11.1.1

References

• GHSA-8qwj-4jxw-m8jw
• security.snyk.io
• CVE-2026-4602
• CWE-681
• CAPEC-310
• OWASP 2021-A6

Related Issues

• OpenLearnX: Critical Authentication Bypass via JWT Signature Verification Disabled Leading to Account Takeover - CVE-2026-44720
• LiquidJS: memoryLimit Bypass through Negative Range Values Leads to Process Crash - CVE-2026-33285
• Forge has a basicConstraints bypass in its certificate chain verification (RFC 5280 violation) - CVE-2026-33896
• jsrsasign is vulnerable to DoS through Infinite Loop when processing zero or negative inputs - CVE-2026-4598

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Tags:

npm

jsrsasign