6.1

CVE-2026-65911: DOMPurify before 3.4.0 XSS via ADD_ATTR/ADD_TAGS State Leakage

Analyzed
AliasesUBUNTU-CVE-2026-65911DEBIAN-CVE-2026-65911
Published 23-07-2026Last modified 27-07-2026

Vulnerability summary

CVE-2026-65911 is a medium (CVSS 6.1) vulnerability in cure53 dompurify. EPSS estimates a 0.33% chance of exploitation in the next 30 days, higher than 26.7% of scored vulnerabilities. 1 public exploit is recorded.

Priority
Routine

Not severe (CVSS 5.1, network access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
6.1/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.33%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits1github

Advisory lineage

Upstream 0 · Downstream 2
RHSA-2026:54517RHSA-2026:58500

Timeline

  1. 23-07-2026
    PublishedVulnerability first disclosed.
  2. 27-07-2026
    Last modifiedVulnerability information updated.

Description

In DOMPurify through 3.3.3, function predicates supplied via ADD_ATTR or ADD_TAGS to DOMPurify.sanitize() persist in internal state (EXTRA_ELEMENT_HANDLING) across subsequent sanitize() calls on the same instance. If a later call on the same instance provides ADD_ATTR or ADD_TAGS as an array rather than a function, the previously set function handler is neither cleared nor overwritten, so it continues to approve attacker-controlled attributes or tags. This can allow dangerous event-handler attributes or forbidden tags (bypassing FORBID_TAGS) to survive sanitization, resulting in cross-site scripting. The vendor (Cure53) considers this an edge case outside DOMPurify's threat model; the referenced advisory lists 3.4.0 as the patched version.

CVSS metrics

7 scores · 4 sources · 2 versions

EPSS trend

Probability

0.33%

Chance of exploitation in the next 30 days

Percentile

27%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.33% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

1 found
  • githubUnverified

    Dompurify

    Maturity: poc

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, user interaction (CVSS vector). Other conditions: not stated in public data.

Cure531 product
Debian1 product
  • node-dompurifyAll versions (No fix recorded) | < 3.4.1+dfsg-1
Ubuntu1 product
  • node-dompurifyAll versions (No fix recorded)

3 vendors · 3 products

References

5 links