CVE-2026-66010: DOMPurify before 3.4.12 fails to execute afterSanitizeElements hook for custom elements allowed via CUSTOM_ELEMENT_HANDLING.tagNameCheck, allowing attributes to bypass application
DOMPurify before 3.4.12 fails to execute afterSanitizeElements hook for custom elements allowed via CUSTOM_ELEMENT_HANDLING.tagNameCheck, allowing attributes to bypass application security policies. Attackers can preserve sensitive attributes on custom elements that later re-inject them into innerHTML sinks, creating second-order XSS gadgets.
Details
Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-66010
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Low exploitation riskCVE-2026-660100.17% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 6% of all scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-66010 | coverage & exploitation status | NVD · CVE.org |
More from NVD Recent CVEs
- mediumCVE-2026-67355: guzzlehttp/guzzle versions before 7.15.1 fail to preserve host-only cookie scope, storing the …2026-08-01
- mediumCVE-2026-67354: guzzlehttp/guzzle versions before 7.15.1 contain an information disclosure vulnerability in Re…2026-08-01
- mediumCVE-2026-67353: guzzlehttp/guzzle versions before 7.15.1 contain a denial of service vulnerability in the Cook…2026-08-01
- highCVE-2026-67352: luci-app-https-dns-proxy contains a stored cross-site scripting vulnerability in the resolver_…2026-08-01
- mediumCVE-2026-67344: ArcadeDB before 26.7.2 fails to enforce the UPDATE_SCHEMA database permission on the ALTER TYP…2026-08-01