CVE-2026-114720 Roundcube CVE debrief

Who should care

Defenders responsible for Roundcube Webmail deployments should assess exposure and apply patches due to the high severity of this vulnerability. They should also review compensating controls for exposed systems while remediation is scheduled and verified. Additionally, defenders should prioritize verifying exposure and applying patches due to the high severity and potential for authenticated attackers to execute arbitrary IMAP commands.

Why it matters

CVE-2026-114720 is a high-severity vulnerability affecting Roundcube Webmail, allowing authenticated attackers to execute arbitrary IMAP commands. Defenders should prioritize verifying exposure and applying patches.

• Authenticated attackers can execute arbitrary IMAP commands
• Potential for data tampering or unauthorized access
• Requires verification of exposure and patch application

Technical summary

The IMAP command injection vulnerability in Roundcube Webmail allows an authenticated attacker to execute arbitrary IMAP commands via CRLF sequences in the `_flag` parameter of the mail/mark action. The vulnerability affects versions before 1.6.20 and 1.7.x before 1.7.5. Upstream fixed this in the commit 'Fix IMAP command injection via CRLF in `_flag` parameter of mail/mark action', which rejects flags containing control, whitespace and IMAP-special characters. Defenders should prioritize verifying exposure and applying patches due to the high severity and potential for authenticated attackers to execute arbitrary IMAP commands.

Defensive priority

Defenders should prioritize verifying exposure and applying patches due to the high severity and potential for authenticated attackers to execute arbitrary IMAP commands.

Recommended defensive actions

• Verify Roundcube Webmail version and apply patches to vulnerable versions
• Restrict access to IMAP services
• Monitor for suspicious IMAP activity
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and source item provide details on the vulnerability, affected versions, and fixed commits. However, additional information on exploitation, victims, or business impact is not available. Defenders should verify exposure and apply patches. Limited source detail is available, so explicit evidence-limit language and defensive verification tasks are necessary.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.