Privilege escalation via IMAP search desynchronization
Published Aug 17, 2026 · Updated Aug 18, 2026
IMAP command injection in Roundcube Webmail before 1.6.18 and 1.7.3 allows remote authenticated users to read data or gain privileges. The mail search handler in program/actions/mail/search.php strips newlines from the assembled SEARCH filter but, before the fix, passed the original search string into the IMAP request without removing CRLF, letting LITERAL+ byte counts desynchronize the command stream and append injected IMAP commands. Exploitation requires valid low-privilege access to Roundcube and an IMAP backend that accepts the malformed search request; impact is bounded to data disclosure, mailbox changes, or privilege changes reachable through injected IMAP operations.
Summary
What happened
IMAP command injection in Roundcube Webmail before 1.6.18 and 1.7.3 allows remote authenticated users to read data or gain privileges. The mail search handler in program/actions/mail/search.php strips newlines from the assembled SEARCH filter but, before the fix, passed the original search string into the IMAP request without removing CRLF, letting LITERAL+ byte counts desynchronize the command stream and append injected IMAP commands. Exploitation requires valid low-privilege access to Roundcube and an IMAP backend that accepts the malformed search request; impact is bounded to data disclosure, mailbox changes, or privilege changes reachable through injected IMAP operations.
The record
- CVE
- CVE-2026-75002
- Published
- Aug 17, 2026
- Updated
- Aug 18, 2026
- Vendor
- Roundcube
- Product
- Roundcube Webmail
- Classifications
- CWE-77, T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 17, 2026CVE publishedPublication date reported by the CVE source.
- Aug 18, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1.6.0 <1.6.18
- Affected versionversion=1.7.0 <1.7.3
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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