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© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2026-47085

24
FAUCET Score

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.)

First published: Jul 16, 2026Last modified: Jul 16, 2026

Impacted Technologies

VendorProductVersion(s)CPE
>= 0, < 3.12.3CPE match
cpe:2.3:a:cyrusimap:cyrus_imap:*:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

4.0MEDIUM

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 Impact
LOW
Integrity Impact
NONE
Availability Impact
NONE
Exploitability Score
2.2
Impact Score
1.4
CvssVersion
3.1

Exploit Intelligence

EPSS Score
0.20%
Probability of exploitation in next 30 days
EPSS Percentile
10.0%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0020 is in the 1st percentile among its peer group of 19,956 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.0 Bluesky, 0.0 Mastodon, and 0.2 GitHub mentions.

Media Mentions

The average CVE in this peer group has 0.0 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Remediation records are not available for this CVE.

References

cyrusimap.org / 3.12/imap/download/release-notes/3.12/x/3.12.3.html
cyrusimap.org / imap/download/release-notes/index.html