Medium severity · published Oct 26, 2026
CVE-2026-116802
DOMPurify before 3.4.17 XSS via SMIL attributeName Guard Bypass in XHTML Mode
New
6.1
CVSS
0.2%
EPSS
No
On KEV
Description
DOMPurify before 3.4.17 contains a cross-site scripting vulnerability that allows attackers to bypass the SMIL attributeName=href guard when PARSER_MEDIA_TYPE is application/xhtml+xml, because transformCaseFunc does not lowercase attribute names. Attackers can submit SVG with an animate or set element using attributeName="href" and a javascript: entry in values to execute script when users click the sanitized link.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 12% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
DO
DOMPurify · cure53
before 3.4.17 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-116802
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-116802
github.com
https://github.com/cure53/DOMPurify/security/advisories/GHSA-c6gr-qvv4-5v3f
www.vulncheck.com
https://www.vulncheck.com/advisories/dompurify-before-3.4.17-xss-via-smil-attributename-guard-bypass-in-xhtml-mode
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