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PatchSiren cyber security CVE debrief

CVE-2026-62641 Roundcube CVE debrief

CVE-2026-62641 is a denial of service vulnerability in Roundcube Webmail's TNEF decoder. The issue affects Roundcube Webmail versions before 1.6.17 and 1.7.x before 1.7.2. The vulnerability is due to a crafted compressed-RTF size. Patched versions are available. Users should apply patches to prevent denial of service attacks. This vulnerability has a CVSS score of 4.3 and a severity of MEDIUM.

Vendor
Roundcube
Product
Webmail
CVSS
MEDIUM 4.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-14
Original CVE updated
2026-07-20
Advisory published
2026-07-14
Advisory updated
2026-07-20

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.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-62641 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-62641

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-62641 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-62641

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental 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.