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CVE-2026-93630

CVE.org · Published

Historical CVEsJSONAI instructions

Record status
Published
Identifier year (not publication year)
2026
Source publication
Source updated
Imported by cveboard
Source snapshot
cve_2026-10-24_midnight_baseline ·

Plain text

CNA source text (English)

Zimbra Collaboration Suite Email HTML Sanitizer Bypass via Hostname Canonicalization

A hostname canonicalization vulnerability in the email HTML sanitizers of Zimbra Collaboration Suite (ZCS) allows an unauthenticated sender to bypass the restriction on forms that target the Zimbra host. DefangFilter and the OWASP ActionAttributePolicy compare the form-action hostname with the request hostname before browser URL canonicalization. A percent-encoded hostname can therefore survive sanitization while the browser submits the form to the normal Zimbra origin with the recipient's authentication cookie. This permits authenticated form requests from a crafted email after the recipient opens it in Classic and submits the form. The issue is present in ZCS 10.1.16 and 10.1.21. It does not bypass an endpoint's CSRF-token checks; a state-changing attack additionally requires an endpoint that accepts the resulting request without that protection.

Scoped product and version facts

Fix information unknown; no fixed version is derived here. Missing information does not prove that no fix exists.

Exploitation unknown; this catalogue does not assess exploitation.

Zimbra Collaboration Suite

Vendor
Zimbra
Product
Zimbra Collaboration Suite
Platforms
Unknown
Default status
unaffected
Zimbra Collaboration Suite · Scoped product and version facts
Version (version)Status (status)Version scheme (versionType)Exclusive end (lessThan)Inclusive end (lessThanOrEqual)Status changes (at → status)
0affectedsemver10.1.21UnavailableNone listed