CVE-2026-4598: Versions of the package jsrsasign before 11.1.1 are vulnerable to Infinite loop via the bnModInverse function

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HIGH 7.5REMOTEUPGRADE

CVE-2026-4598 is a high-severity flaw (CVSS 7.5) affecting jsrsasign. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Versions of the package jsrsasign before 11.1.1 are vulnerable to Infinite loop via the bnModInverse function in ext/jsbn2.js when the BigInteger.modInverse implementation receives zero or negative inputs, allowing an attacker to hang the process permanently by supplying such crafted values (e.g., modInverse(0, m) or modInverse(-1, m)).

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 54%)
CISA exploited list	No
Weakness	CWE-835, CWE-1287
Published	2026-03-23
Last modified	2026-09-10

Publisher (CNA): Snyk · Vendor: kjur

Last updated 2026-09-10 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-03-23 06:16 UTCPublished CVE record published
2026-09-10 13:20 UTCUpdated Record last modified

kjur jsrsasign UPGRADE

Affected: < 11.1.1

Fixed in: 11.1.1

Safe to downgrade to: no unaffected older release

1. Check installed version

npm ls jsrsasign

2. UPGRADE to 11.1.1

npm install jsrsasign@">=11.1.1"

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-4598?

jsrsasign: upgrade to 11.1.1. Exact commands for each OS are on this page.

Is CVE-2026-4598 being exploited?

CVE-2026-4598 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-4598 affect?

CVE-2026-4598 affects jsrsasign. Severity is high (CVSS 7.5). Versions of the package jsrsasign before 11.1.1 are vulnerable to Infinite loop via the bnModInverse function in ext/jsbn2.js when the BigInteger.modInverse implementation receives zero or negative inputs, allowing an attacker to hang the p

How urgent is CVE-2026-4598?

Priority 48/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-4602 HIGH 7.5 UPGRADE Versions of the package jsrsasign before 11.1.1 are vulnerable to Incorrect Conversion between Numeric Types d
CVE-2026-4601 HIGH 8.7 UPGRADE Versions of the package jsrsasign before 11.1.1 are vulnerable to Missing Cryptographic Step via the KJUR.cryp
CVE-2026-4600 HIGH 7.4 UPGRADE Versions of the package jsrsasign before 11.1.1 are vulnerable to Improper Verification of Cryptographic Signa
CVE-2026-4599 CRITICAL 9.1 UPGRADE Versions of the package jsrsasign from 7.0.0 and before 11.1.1 are vulnerable to Incomplete Comparison with Mi
CVE-2026-4603 MEDIUM 5.9 UPGRADE Versions of the package jsrsasign before 11.1.1 are vulnerable to Division by zero due to the RSASetPublic/KEY

References

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