CVE-2026-4598: Jsrsasign Denial of Service Vulnerability

HIGH
Advisory Identifier: GHSA-8g7p-jf3g-gxcp
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CVSS 7.5
CWE-1287 CWE-835
Published
Advisory Summary

CVE-2026-4598 is a HIGH (CVSS 7.5) denial of service vulnerability (CWE-1287: Improper Validation of Specified Type of Input) affecting Jsrsasign libraries in the npm ecosystem. The issue involves jsrsasign is vulnerable to dos through infinite loop when processing zero or negative inputs. Remediation is available by upgrading affected packages to version 11.1.1.

CVE-2026-4598 at a Glance

CVE Identifier CVE-2026-4598
GHSA Identifier GHSA-8g7p-jf3g-gxcp
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-1287: Improper Validation of Specified Type of Input
Affected Product Jsrsasign
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-4598

To remediate this vulnerability, upgrade all affected Jsrsasign dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

jsrsasign fixed: 11.1.1 
npm install jsrsasign@11.1.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls jsrsasign

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-4598, inspect your project dependencies using npm:

npm ls jsrsasign

Analyze the terminal output to locate any version of Jsrsasign in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 11.1.1), your application is affected.

Note: The npm ls jsrsasign command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-1287: Improper Validation of Specified Type of Input, where the product receives input that is expected to be of a certain type, but it does not validate or incorrectly validates that the input is actually of the expected type. In Jsrsasign, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

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)).

CVE-2026-4598 Affected Jsrsasign Versions

1 component(s)
Fixed Versions:
11.1.1
Product / Package Ecosystem Affected Versions Fixed Version
jsrsasign
npm/jsrsasign
npm
< 11.1.1
11.1.1

References

NVD — CVE-2026-4598 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-4598
Jsrsasign Source Repository REPOSITORY
https://github.com/kjur/jsrsasign/pull/648
Security Fix Commit FIX COMMIT
https://github.com/kjur/jsrsasign/commit/ca5b027240287a1e71fe63019fc4400332594323
Jsrsasign Security Information SECURITY
https://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15370938
Jsrsasign Security Information SECURITY
https://security.snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-15812263
Jsrsasign Security Information SECURITY
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4598.json
Jsrsasign Source Repository REPOSITORY
https://github.com/kjur/jsrsasign
Jsrsasign Source Repository REPOSITORY
https://gist.github.com/Kr0emer/a1bf5cd4547cc630d2dcc5e761de8264
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=2450210
Jsrsasign Security Information SECURITY
https://access.redhat.com/security/cve/CVE-2026-4598
access.redhat.com/errata/rhsa-2026:67... WEB
https://access.redhat.com/errata/RHSA-2026:6720
access.redhat.com/errata/rhsa-2026:65... WEB
https://access.redhat.com/errata/RHSA-2026:6568
access.redhat.com/errata/rhsa-2026:23... WEB
https://access.redhat.com/errata/RHSA-2026:23361
access.redhat.com/errata/rhsa-2026:22... WEB
https://access.redhat.com/errata/RHSA-2026:22840
access.redhat.com/errata/rhsa-2026:19... WEB
https://access.redhat.com/errata/RHSA-2026:19410
access.redhat.com/errata/rhsa-2026:19... WEB
https://access.redhat.com/errata/RHSA-2026:19409
access.redhat.com/errata/rhsa-2026:19... WEB
https://access.redhat.com/errata/RHSA-2026:19375

Frequently Asked Questions

What is CVE-2026-4598?
CVE-2026-4598 is a security vulnerability in Jsrsasign involving jsrsasign is vulnerable to DoS through Infinite Loop when processing zero or negative inputs under CWE-1287: Improper Validation of Specified Type of Input.
Which Jsrsasign versions are affected?
Affected versions include releases prior to 11.1.1 across affected packages: jsrsasign.
What version fixes CVE-2026-4598?
Upgrading to 11.1.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is jsrsasign affected?
Yes, jsrsasign is affected in releases prior to 11.1.1. Upgrade your dependency to 11.1.1 or later.
What is the CVSS score of CVE-2026-4598?
CVE-2026-4598 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-4598?
CVE-2026-4598 is classified under CWE-1287: Improper Validation of Specified Type of Input (The product receives input that is expected to be of a certain type, but it does not validate or incorrectly validates that the input is actually of the expected type.).
How can I check npm dependencies for CVE-2026-4598?
Run the dependency tree command: 'npm ls jsrsasign'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-8g7p-jf3g-gxcp",
  "modified" : "2026-07-21T13:42:15Z",
  "published" : "2026-03-23T06:30:29Z",
  "aliases" : [ "CVE-2026-4598" ],
  "summary" : "jsrsasign is vulnerable to DoS through Infinite Loop when processing zero or negative inputs",
  "details" : "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)).",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "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:P"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "jsrsasign"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "11.1.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-4598"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kjur/jsrsasign/pull/648"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kjur/jsrsasign/commit/ca5b027240287a1e71fe63019fc4400332594323"
  }, {
    "type" : "WEB",
    "url" : "https://security.snyk.io/vuln/SNYK-JS-JSRSASIGN-15370938"
  }, {
    "type" : "WEB",
    "url" : "https://security.snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-15812263"
  }, {
    "type" : "WEB",
    "url" : "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4598.json"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/kjur/jsrsasign"
  }, {
    "type" : "WEB",
    "url" : "https://gist.github.com/Kr0emer/a1bf5cd4547cc630d2dcc5e761de8264"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2450210"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/security/cve/CVE-2026-4598"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:6720"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:6568"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:23361"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:22840"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:19410"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:19409"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:19375"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1287", "CWE-835" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-29T15:51:28Z",
    "nvd_published_at" : "2026-03-23T06:16:21Z"
  }
}