CVE-2026-114719 Roundcube CVE debrief

Who should care

Defenders responsible for Roundcube Webmail installations, particularly those using versions before 1.6.20 or 1.7.5, should assess exposure and prioritize patching. This includes reviewing system logs for potential exploitation attempts and ensuring that CSRF token validation is implemented for actions in web applications.

Why it matters

This CSRF validation bypass vulnerability in Roundcube Webmail's mark-as-junk action could allow attackers to perform unauthorized actions. Defenders should prioritize verifying and applying patches, assessing exposure, and implementing CSRF token validation.

• Potential for unauthorized actions via CSRF bypass
• Need for verification of patch application and exposure assessment

Technical summary

The markasjunk plugin in Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 does not properly constrain input mode when reading the _uid parameter from POST data and passing it to rcmail::get_uids(). This allows attackers to perform actions without a valid CSRF token. The issue was addressed by explicitly passing rcube_utils::INPUT_POST. Upstream fixed this in the commit “Fix CSRF validation bypass in the mark-as-junk action”. Defenders should prioritize verifying and applying patches, assessing exposure, and implementing CSRF token validation.

Defensive priority

Defenders should prioritize verifying and applying patches for Roundcube Webmail versions 1.6.20 and 1.7.5, and assess exposure in their environments.

Recommended defensive actions

• Verify and apply patches for Roundcube Webmail versions 1.6.20 and 1.7.5
• Assess exposure in environments using affected versions of Roundcube Webmail
• Implement CSRF token validation for actions in web applications
• 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 vulnerability is caused by the markasjunk plugin reading the _uid parameter from POST data but passing it to rcmail::get_uids() without constraining the input mode. This could allow values re-read inside that helper to be taken from the query string, enabling the action to be carried out without a valid CSRF token.

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.