CVE-2026-47085
CVSS Score
4.0
EPSS Score
0.0%
EPSS Percentile
0th
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.)
| CWE | CWE-340 |
| Vendor | cyrusimap |
| Product | cyrus imap |
| Published | Jul 16, 2026 |
| Last Updated | Jul 16, 2026 |
Stay Ahead of the Next One
Get instant alerts for cyrusimap cyrus imap
Be the first to know when new medium vulnerabilities affecting cyrusimap cyrus imap are published — delivered to Slack, Telegram or Discord.
Get Free Alerts →
Free · No credit card · 60 sec setup
CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:N Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
Low
Integrity
None
Availability
None
Affected Versions
cyrusimap / Cyrus IMAP
0 < 3.12.3