Regular expression denial of service in jquery-validation

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

not scored

EPSS

• CVE-2021-43306: 1.52% estimated exploitation activity in the next 30 days; percentile 74.66 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

An exponential ReDoS (Regular Expression Denial of Service) can be triggered in the jquery-validation npm package, when an attacker is able to supply arbitrary input to the url2 method

Published by the source

3 Jun 2022, 00:00 UTC

Last modified by the source

12 Nov 2024, 14:55 UTC

Source last checked

26 Oct 2026, 12:31 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-j9m2-h2pv-wvph

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-j9m2-h2pv-wvph

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# Patch Next advisory brief: CVE-2021-43306

Advisory: Regular expression denial of service in jquery-validation
IDs: CVE-2021-43306, GHSA-j9m2-h2pv-wvph
Record: https://patchnext.com/advisories/cve-2021-43306 (revision 2, source checked 26 Oct 2026, 12:31 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Unrated
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: jquery-validation 1.19.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm jquery-validation: affected < 1.19.4; fixed in 1.19.4

## Suggested inspection (read-only)
- `npm ls jquery-validation --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on jquery-validation.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-j9m2-h2pv-wvph (OSV record GHSA-j9m2-h2pv-wvph lists affected ranges: npm jquery-validation >=0 <1.19.4 (fixed))
- Verified: https://github.com/advisories/GHSA-j9m2-h2pv-wvph (GitHub-reviewed advisory GHSA-j9m2-h2pv-wvph lists affected ranges: npm jquery-validation >=0 <1.19.4)

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