CVE-2026-49458: DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG

Q: How do I fix CVE-2026-49458?

dompurify: upgrade to 3.4.6. Exact commands for each OS are on this page.

Q: Is CVE-2026-49458 being exploited?

CVE-2026-49458 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-49458 affect?

CVE-2026-49458 affects dompurify. Severity is medium (CVSS 6.1). DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Prior to 3.4.6, DOMPurify.sanitize(node, { IN_PLACE: true }) accepted same-origin foreign-realm DOM nodes while follow-on checks used parent-realm constructor

Q: How urgent is CVE-2026-49458?

Priority 35/100. Public exploit reference

Routine

MEDIUM 6.1UPGRADE

CVE-2026-49458 is a medium-severity flaw (CVSS 6.1) affecting dompurify. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Prior to 3.4.6, DOMPurify.sanitize(node, { IN_PLACE: true }) accepted same-origin foreign-realm DOM nodes while follow-on checks used parent-realm constructors, causing instanceof checks for forms, named node maps, document fragments, and elements to fail and skip clobber, template-content, and shadow-DOM sanitization branches so executable markup could survive. Thi

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	6.1 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.4% (top 66%)
CISA exploited list	No
Weakness	CWE-79, CWE-501, CWE-693
Published	2026-07-14
Last modified	2026-10-24

Publisher (CNA): GitHub, Inc. · Vendor: cure53

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-14 21:17 UTCPublished CVE record published
2026-10-24 21:10 UTCUpdated Record last modified

cure53 dompurify UPGRADE

Affected: < 3.4.6

Fixed in: 3.4.6

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy dompurify || rpm -q dompurify || dompurify --version

2. UPGRADE to 3.4.6 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade dompurify

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade dompurify

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

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-2026-49458?

dompurify: upgrade to 3.4.6. Exact commands for each OS are on this page.

Is CVE-2026-49458 being exploited?

CVE-2026-49458 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-2026-49458 affect?

CVE-2026-49458 affects dompurify. Severity is medium (CVSS 6.1). DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Prior to 3.4.6, DOMPurify.sanitize(node, { IN_PLACE: true }) accepted same-origin foreign-realm DOM nodes while follow-on checks used parent-realm constructor

How urgent is CVE-2026-49458?

Priority 35/100. Public exploit reference

Related CVEs

CVE-2026-47423 HIGH 8.2 DOWNGRADE DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG
CVE-2026-49978 MEDIUM 6.1 UPGRADE DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG
CVE-2026-49459 MEDIUM 6.1 UPGRADE DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG
CVE-2026-65898 HIGH 7.2 UPGRADE DOMPurify before 3.4.11 fails to clone the ALLOWED_ATTR allowlist when setConfig() is used with an uponSanitiz
CVE-2026-65899 MEDIUM 6.1 UPGRADE DOMPurify 3.0.0 before 3.4.9 does not reset the retained Trusted Types policy when clearConfig() is called, so

References

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