CVE-2026-61907: CWE-863 Incorrect Authorization in cyrusimap Cyrus IMAP
CVE-2026-61907 is a medium severity vulnerability in Cyrus IMAP before version 3.12.4. It involves an incorrect authorization issue where the JMAP snooze feature bypasses mailbox access control lists (ACLs). An authenticated user with insert permissions on another user's snoozed mailbox can insert mail into that user's inbox or other mailboxes if the mailbox ID is known, despite lacking insert permissions on the target mailbox.
AI Analysis
Technical Summary
This vulnerability in Cyrus IMAP versions 3.9.0 and 3.11.0 allows an authenticated user who has insert permissions on a snoozed mailbox of another user to bypass ACL restrictions. Specifically, the JMAP snooze functionality does not properly enforce destination mailbox ACLs, enabling insertion of mail into the target user's inbox or any other mailbox with a known ID, even if the attacker lacks explicit insert permissions on those mailboxes. This is classified as CWE-863 (Incorrect Authorization).
Potential Impact
The vulnerability allows unauthorized insertion of email messages into other users' mailboxes, potentially leading to mailbox pollution or manipulation. There is no impact on confidentiality or availability reported, only integrity is affected. No known exploits are reported in the wild.
Mitigation Recommendations
No official patch or remediation is currently confirmed. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict insert permissions carefully and monitor mailbox access policies to limit potential abuse.
CVE-2026-61907: CWE-863 Incorrect Authorization in cyrusimap Cyrus IMAP
Description
CVE-2026-61907 is a medium severity vulnerability in Cyrus IMAP before version 3.12.4. It involves an incorrect authorization issue where the JMAP snooze feature bypasses mailbox access control lists (ACLs). An authenticated user with insert permissions on another user's snoozed mailbox can insert mail into that user's inbox or other mailboxes if the mailbox ID is known, despite lacking insert permissions on the target mailbox.
CVSS v3.1
Score 4.3medium
Affected software
pkg:github/cyrusimap/cyrus-imapdRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability in Cyrus IMAP versions 3.9.0 and 3.11.0 allows an authenticated user who has insert permissions on a snoozed mailbox of another user to bypass ACL restrictions. Specifically, the JMAP snooze functionality does not properly enforce destination mailbox ACLs, enabling insertion of mail into the target user's inbox or any other mailbox with a known ID, even if the attacker lacks explicit insert permissions on those mailboxes. This is classified as CWE-863 (Incorrect Authorization).
Potential Impact
The vulnerability allows unauthorized insertion of email messages into other users' mailboxes, potentially leading to mailbox pollution or manipulation. There is no impact on confidentiality or availability reported, only integrity is affected. No known exploits are reported in the wild.
Mitigation Recommendations
No official patch or remediation is currently confirmed. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict insert permissions carefully and monitor mailbox access policies to limit potential abuse.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mitre
- Date Reserved
- 2026-07-13T00:00:00.000Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6aa28ec9acd9273b4901d48f
Added to database: 09/10/2026, 11:04:41 UTC
Last enriched: 09/10/2026, 11:07:23 UTC
Last updated: 09/10/2026, 11:59:27 UTC
Views: 6
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