Roundcube Webmail before 1.6.21 and 1.7.x before 1.7.6 contains an IMAP command injection vulnerability that allows
Source GCVE Database
Not known to be exploited · CVSS 7.4 High : upgrade to 1.7.6 or 1.6.21 soon.
Data as of 11 Nov 2026, 22:21 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 7.4 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 6.8 |
- Patch
- Available – fixed in 1.7.6, 1.6.21
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 11 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 11 Nov 2026.
What to do
Upgrade Webmail to 1.7.6 or 1.6.21.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| RoundcubeWebmail | Affected
| Fixed in
|
| RoundcubeWebmail | Affected
| Fixed in
|
PackagistWebmailpkg:composer/WebmailOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available in Roundcube Webmail versions 1.6.21 and 1.7.6. Users should upgrade to these or later versions to remediate this vulnerability. Until patched, disabling the messages_cache feature may mitigate the risk by preventing the injection vector.
Description
Roundcube Webmail versions before 1.6.21 and 1.7.x before 1.7.6 have an IMAP command injection vulnerability. This flaw allows attackers to inject IMAP commands via CRLF sequences in the _uid parameter when the messages_cache feature is enabled. Exploitation requires a logged-in victim to open a specially crafted GET link, which can lead to unauthorized deletion of messages, modification of message flags, or unauthorized mailbox access via SETACL commands.
References
- nvd.nist.gov/vuln/detail/CVE-2026-126813 (opens in a new tab)
- github.com/roundcube/roundcubemail/commit/2ea63692178cab5cea486c7c630901b7f6852c80 (opens in a new tab)
- github.com/roundcube/roundcubemail/commit/4cb1cf106b9ca5d465ed4924f2fab5d5108edfeb (opens in a new tab)
- github.com/roundcube/roundcubemail/commit/d1dda13597ceed9df49d434a8d88b758bcf6ef5c (opens in a new tab)
- github.com/roundcube/roundcubemail/blob/1.7.5/program/lib/Roundcube/rcube_imap_generic.php (opens in a new tab)
- github.com/roundcube/roundcubemail/releases/tag/1.6.21 (opens in a new tab)
- github.com/roundcube/roundcubemail/releases/tag/1.7.6 (opens in a new tab)
- roundcube.net/news/2026/11/09/security-updates-1.6.21-and-1.7.6 (opens in a new tab)
- vulncheck.com/advisories/roundcube-webmail-before-1.6.21-and-1.7.6-imap-command-injection-via-uid (opens in a new tab)