CVE-2026-62641 Roundcube CVE debrief

Who should care

Users of Roundcube Webmail, particularly those responsible for maintaining and securing email services, should apply patches to prevent denial of service attacks. This vulnerability affects versions before 1.6.17 and 1.7.x before 1.7.2.

Technical summary

CVE-2026-62641 is a denial of service vulnerability in Roundcube Webmail's TNEF decoder. The issue arises from a crafted compressed-RTF size. Affected versions are before 1.6.17 and 1.7.x before 1.7.2. The vulnerability has a CVSS score of 4.3 and a severity of MEDIUM. Users of Roundcube Webmail should apply patches to prevent denial of service attacks. This can be achieved by updating to the latest version, verifying the integrity of the update, and ensuring that the TNEF decoder is properly configured. Additionally, monitoring for suspicious activity related to crafted compressed-RTF sizes can help detect potential attacks. It is also essential to review compensating controls for exposed systems while remediation is scheduled and verified.

Defensive priority

Apply patches to prevent denial of service attacks. Inventory and update vulnerable Roundcube Webmail installations. Monitor for suspicious activity related to crafted compressed-RTF sizes.

Recommended defensive actions

• Apply patches 1.6.17 or 1.7.2 to fix the TNEF decoder denial of service vulnerability
• Inventory and update vulnerable Roundcube Webmail installations
• Monitor for suspicious activity related to crafted compressed-RTF sizes
• 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 was published on 2026-07-14T16:17:04.377Z and was last modified on 2026-07-20T12:56:55.210Z. The NVD entry is currently Analyzed. This information is based on the provided source corpus. Further verification is recommended to ensure accuracy.

Official resources