CVE-2026-116802 DOMPurify before 3.4.17 XSS via SMIL attributeName Guard Bypass in XHTML Mode
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-116802?
CVE-2026-116802 is a medium-severity vulnerability in cure53 DOMPurify, published on 26 Oct 2026.
Official 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.
Weakness: CWE-79
Which versions are affected by CVE-2026-116802?
2 open source packages ship an affected version, including dompurify.
| Package | Affected | Fixed in |
|---|---|---|
dompurify npm | All versions | 3.4.17 |
dompurify npm | All versions | 3.4.17 |
How do I fix CVE-2026-116802?
Upgrade dompurify to 3.4.17 or later.
Is CVE-2026-116802 being exploited?
There is no known exploitation of CVE-2026-116802 in the wild and no public exploit code.
Sources
Also known as CLSA-2026-1792929353, CLSA-2026-1792929831, CLSA-2026-1792929955, CLSA-2026-1792930059, CLSA-2026-1792930172, CLSA-2026-1792930526 and 31 more.