CVE-2026-4602: jsrsasign · Incorrect Conversion Between Numeric Types
Affects jsrsasignSource CVE Database V5
Public exploit available · CVSS 8.7 High : upgrade to 11.1.1 as a priority.
Data as of 30 Oct 2026, 06:59 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 42% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 11.1.1
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:PExploitation evidence
Disclosed: evidence found.
CVE published 23 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CVSS exploit maturity: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade jsrsasign to 11.1.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| jsrsasign | Affected
| Fixed in
|
| org.webjars.npm:jsrsasign | Affected
| Fixed in– |
npmjsrsasignpkg:npm/jsrsasignOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Currently, there is no available fix or mitigation that meets Red Hat's criteria for ease of use, deployment, applicability, or stability. If you cannot patch yet, affected systems remain vulnerable. Consider limiting exposure of affected components where possible.
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.
References
- security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15371175 (opens in a new tab)
- security.snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-15812274 (opens in a new tab)
- gist.github.com/Kr0emer/7ecd2be7d17419e4677315ef3758faf5 (opens in a new tab)
- github.com/kjur/jsrsasign/pull/650 (opens in a new tab)
- github.com/kjur/jsrsasign/commit/5ea1c32bb2aa894b4bd29849839afe4f98728195 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-4602 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2450206 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4602.json (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:19409 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:19410 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:6720 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:6568 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:19375 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:6912 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:6926 (opens in a new tab)