CVE-2026-114725 Roundcube CVE debrief

Who should care

Defenders responsible for Roundcube Webmail deployments, especially those with versions before 1.6.20 and 1.7.5, should assess exposure and prioritize patching or updating to mitigate potential risks.

Why it matters

CVE-2026-114725 is a medium-severity vulnerability affecting Roundcube Webmail, allowing authenticated attackers to inject arbitrary headers into outgoing messages. Defenders should prioritize verifying exposure and applying patches to mitigate potential risks.

• Potential for unauthorized modification of outgoing messages
• Risk of email header injection
• Need for verification of affected versions and patch application

Technical summary

The CVE-2026-114725 vulnerability affects Roundcube Webmail before versions 1.6.20 and 1.7.5. An authenticated attacker can inject arbitrary headers into an outgoing message via specific parameters, including References, In-Reply-To, Message-ID, and From. The vulnerability was fixed in commits that normalize whitespace in every string header value. This technical issue allows for potential unauthorized modifications to email headers, emphasizing the need for prompt patching and verification of affected systems. Defenders should focus on applying the available patches and reviewing system configurations to prevent exploitation.

Defensive priority

Defenders should prioritize verifying exposure in their Roundcube Webmail deployments, especially for versions before 1.6.20 and 1.7.5, and apply patches or updates as soon as possible.

Recommended defensive actions

• Verify Roundcube Webmail version and apply patches or updates to versions 1.6.20 or 1.7.5
• Review and restrict access to authenticated users
• Monitor outgoing messages for suspicious headers
• Conduct a thorough review of system logs for any signs of exploitation
• Implement additional monitoring for unusual email activity
• Perform a detailed assessment of the vulnerability's impact on the organization's specific environment
• Document and track the verification and remediation process for future reference

Evidence notes

The CVE record and source item provide details on the vulnerability, affected versions, and patches. However, there is limited information on potential exploitation or victim impact. Defenders should verify the affected versions in their deployments and review the official advisory for specific guidance. The lack of detailed information on exploitation or impact necessitates a cautious approach, focusing on verifying exposure and applying patches as a precautionary measure.

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.