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GHSA-cjmm-f4jc-qw8r — dompurify

GHSA-cjmm-f4jc-qw8r is a Cross-site Scripting (XSS) vulnerability in dompurify. A fix is available for dompurify — see the affected versions and patch details below.

DOMPurify ADD_ATTR predicate skips URI validation

Also known asCVE-2026-65912
Published
Apr 3, 2026
Updated
Sep 10, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Sep 19, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-cjmm-f4jc-qw8r.

EPSS Exploitation Probability

via FIRST.org ↗
0.2%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs7th percentile — riskier than 7% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

5Kother npm packages depend on this — each one inherits the vulnerability until it's patched upstream
dompurifynpm
46.3Mdownloads / week

Description

Summary

DOMPurify allows ADD_ATTR to be provided as a predicate function via EXTRA_ELEMENT_HANDLING.attributeCheck. When the predicate returns true, _isValidAttribute short-circuits the attribute check before URI-safe validation runs. An attacker who supplies a predicate that accepts specific attribute/tag combinations can then sanitize input such as <a href="javascript:alert(document.domain)"> and have the javascript: URL survive, because URI validation is skipped for that attribute while other checks still pass. The provided PoC accepts href for anchors and then triggers a click inside an iframe, showing that the sanitized payload executes despite the protocol bypass.

Impact

Predicate-based allowlisting bypasses DOMPurify's URI validation, allowing unsafe protocols such as javascript: to reach the DOM and execute whenever the link is activated, resulting in DOM-based XSS.

Credits

Identified by Cantina’s Apex (https://www.cantina.security).

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
📦npmdompurifyall versions3.3.2npm install dompurify@3.3.2

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for dompurify, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update dompurify to 3.3.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-cjmm-f4jc-qw8r is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-cjmm-f4jc-qw8r can be triaged on real exposure rather than presence alone.

Tailored to GHSA-cjmm-f4jc-qw8r. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

This cross-site scripting (XSS) vulnerability in DOMPurify arises when applications configure ADD_ATTR as a predicate function through EXTRA_ELEMENT_HANDLING.attributeCheck. An attacker could exploit this by crafting malicious input that bypasses URI validation, leading to the execution of unsafe javascript: protocols…

ProductFixed inAdvisory
Red Hat Hardened Imagesgrafana13-1-main-13.1.3-0.1.1.hum1RHSA-2026:54517
Red Hat Hardened Imagesgrafana12-4-main-12.4.8-0.1.2.hum1RHSA-2026:58500

Frequently Asked Questions

## Summary DOMPurify allows `ADD_ATTR` to be provided as a predicate function via `EXTRA_ELEMENT_HANDLING.attributeCheck`. When the predicate returns `true`, `_isValidAttribute` short-circuits the attribute check before URI-safe validation runs. An attacker who supplies a predicate that accepts specific attribute/tag combinations can then sanitize input such as `<a href="javascript:alert(document.domain)">` and have the `javascript:` URL survive, because URI validation is skipped for that attribute while other checks still pass. The provided PoC accepts `href` for anchors and then triggers a c
O3 Security · Impact-Aware SCA

Is GHSA-cjmm-f4jc-qw8r in your dependencies?

O3 Security finds GHSA-cjmm-f4jc-qw8r across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

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GHSA-cjmm-f4jc-qw8r: dompurify XSS | O3 Security