CVE-2026-65902
MEDIUM
MEDIUM
Priority: 0.02
BB Relevance:
61/100
Published: 2026-07-23
Modified: 2026-10-29
First seen: 2026-10-29
Status: active
Attack Surface
Network
Low Complexity
No Auth
CVSS Vector Breakdown
AV:
Network
AC:
Low
PR:
None
UI:
Passive
AT:
None
VC:
Low
VI:
Low
VA:
None
Description
DOMPurify before 3.4.7 passes direct references to the module-level DEFAULT_ALLOWED_TAGS and DEFAULT_ALLOWED_ATTR sets to the uponSanitizeElement and uponSanitizeAttribute hooks via data.allowedTags / data.allowedAttributes when sanitize is called without an explicit cfg.ALLOWED_TAGS / cfg.ALLOWED_ATTR array. A hook that mutates these fields permanently widens the default allow-lists for the lifetime of the DOMPurify instance, so all subsequent default-config sanitize calls inherit the widened defaults and attacker payloads using the poisoned tag/attribute name survive sanitization. removeAllHooks(), clearConfig(), and passing a fresh cfg do not recover the state; only constructing a new DOMPurify instance does.
Weakness Classification (1)
References & Advisories (3)
Third Party Advisory
Patch
Exploit
Third Party Advisory