CVE-2026-47085
MEDIUM
MEDIUM
Priority: 0.01
BB Relevance:
58/100
Published: 2026-07-16
Modified: 2026-10-24
First seen: 2026-10-29
Status: active
Attack Surface
Network
No Auth
No Interaction
Scope Change
CVSS Vector Breakdown
AV:
Network
AC:
High
PR:
None
UI:
None
S:
Changed
C:
Low
I:
None
A:
None
Description
An issue was discovered in cyrus-imapd in Cyrus IMAP through 3.12.2. URLAUTH token forgery can occur via a missing mboxkey. If an attacker knew a folder name on the victim's account for which the victim had never issued an auth URL, they could forge a working URLAUTH token by computing an HMAC-SHA1 value with a predictable key, giving them read access to the mailbox. (URLAUTH is an obscure feature, meaning that the odds of any user actually being susceptible to this attack are very low. Perhaps no public clients use URLAUTH.)