How severe is CVE-2026-65904?

CVE-2026-65904 has a CVSS 3.x base score of 4.7, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-65904 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-65904?

CVE-2026-65904 affects Cure53 Dompurify. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-65904?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2026-65904 published?

CVE-2026-65904 was published on 2026-07-23 and last updated on 2026-07-28.

CVE-2026-65904

CVE-2026-65904 is a medium-severity vulnerability in Cure53 Dompurify with a CVSS 3.x base score of 4.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-754.

Key facts

Severity: Medium (CVSS 3.x base score 4.7)
CVSS v4: 2.3
EPSS exploit prediction: 0% (8th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-754
Affected product: Cure53 Dompurify
Published: 2026-07-23
Last modified: 2026-07-28

Description

DOMPurify through 3.3.3 fails to sanitize DOM elements passed via IN_PLACE mode when the element originates from a different window/realm (e.g., an iframe's contentDocument). A cross-realm instanceof check in the private _isNode() function returns false for foreign-realm nodes, causing DOMPurify to stringify the element (yielding '[object HTMLDivElement]'), silently reset IN_PLACE to false, and return the unsanitized element unchanged with any XSS payloads intact.

Frequently asked questions

What is CVE-2026-65904?: DOMPurify through 3.3.3 fails to sanitize DOM elements passed via IN_PLACE mode when the element originates from a different window/realm (e.g., an iframe's contentDocument). A cross-realm instanceof check in the private _isNode() function returns false for foreign-realm nodes, causing DOMPurify to stringify the element (yielding '[object HTMLDivElement]'), silently reset IN_PLACE to false, and return the unsanitized element unchanged with any XSS payloads intact.
How severe is CVE-2026-65904?: CVE-2026-65904 has a CVSS 3.x base score of 4.7, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-65904 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-65904?: CVE-2026-65904 affects Cure53 Dompurify. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-65904?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-65904 published?: CVE-2026-65904 was published on 2026-07-23 and last updated on 2026-07-28.

References

Affected products (1)

cpe:2.3:a:cure53:dompurify:*:*:*:*:*:*:*:*

More vulnerabilities in Cure53 Dompurify

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