CVE-2026-65899: DOMPurify 3.0.0 before 3.4.9 does not reset the retained Trusted Types policy when clearConfig() is called, so

Routine

MEDIUM 6.1UPGRADE

CVE-2026-65899 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 3.0.0 before 3.4.9 does not reset the retained Trusted Types policy when clearConfig() is called, so a DOMPurify instance reused across trust boundaries stays bound to a previously supplied TRUSTED_TYPES_POLICY. A later caller that requests RETURN_TRUSTED_TYPE output receives a TrustedHTML object created by the old (potentially unsafe) policy rather than a clean default, which can lead to script execution at a Trusted Types sink. Passin

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-693
Published	2026-07-23
Last modified	2026-10-24

Publisher (CNA): VulnCheck · Vendor: cure53

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

Am I affected?

Timeline

2026-07-23 14:18 UTCPublished CVE record published
2026-10-24 13:10 UTCUpdated Record last modified

cure53 dompurify UPGRADE

Affected: >= 3.0.0 and < 3.4.9

Fixed in: 3.4.9

Safe to downgrade to: a release before 3.0.0

1. Check installed version

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

2. UPGRADE to 3.4.9 (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.

3. If no update is available yet, DOWNGRADE to a release before 3.0.0 (Debian / Ubuntu)

apt-cache madison dompurify sudo apt install dompurify=<VERSION_BEFORE_3.0.0> sudo apt-mark hold dompurify

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list dompurify sudo dnf downgrade dompurify-<VERSION_BEFORE_3.0.0> sudo dnf versionlock add dompurify

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Exact fixes by distribution

npm · dompurify · FIXED · 3.4.9 · vulnerable: < 3.4.9 · source

npm install dompurify@">=3.4.9" npm ls dompurify

Fedora ELN · selinux-policy · FIXED · 45.23-1.eln159 · FEDORA-2026-3668c969a2 · source

sudo dnf upgrade --advisory=FEDORA-2026-3668c969a2

Fedora 46 · sugar-toolkit-gtk3 · FIXED · 0.122-2.fc46 · FEDORA-2026-d11eb2faf0 · source

sudo dnf upgrade --advisory=FEDORA-2026-d11eb2faf0

Debian 12 · node-dompurify · NO FIX YET

Debian 13 · node-dompurify · NO FIX YET

RHEL 10 · ceph · DEFERRED

RHEL 10 · cockpit-image-builder · DEFERRED

RHEL 10 · grafana · DEFERRED

RHEL 10 · grafana-pcp · NOT AFFECTED

RHEL 8 · grafana · DEFERRED

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Write-up: github.com/cure53/DOMPurify/security/advisories/GHSA-vxr8-fq34-vvx9

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-2026-65899?

dompurify: upgrade to 3.4.9. Exact commands for each OS are on this page.

Is CVE-2026-65899 being exploited?

CVE-2026-65899 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-2026-65899 affect?

CVE-2026-65899 affects dompurify. Severity is medium (CVSS 6.1). DOMPurify 3.0.0 before 3.4.9 does not reset the retained Trusted Types policy when clearConfig() is called, so a DOMPurify instance reused across trust boundaries stays bound to a previously supplied TRUSTED_TYPES_POLICY. A later caller tha

How urgent is CVE-2026-65899?

Priority 35/100. Public exploit reference

Related CVEs

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CVE-2026-65902 MEDIUM 6.1 UPGRADE DOMPurify before 3.4.7 (affected versions <= 3.4.5) passes direct references to the module-level DEFAULT_ALLOW
CVE-2026-65911 MEDIUM 6.1 UPGRADE In DOMPurify through 3.3.3, function predicates supplied via ADD_ATTR or ADD_TAGS to DOMPurify.sanitize() pers
CVE-2026-65900 MEDIUM 6.1 UPGRADE DOMPurify versions >=3.0.0 and before 3.4.8, when configured with SAFE_FOR_TEMPLATES together with a DOM outpu
CVE-2026-65903 MEDIUM 6.1 UPGRADE DOMPurify before 3.4.0 contains a logic error in the ADD_TAGS function where short-circuit evaluation allows f

References

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