Vulnerability in Kiteworks Email Protection Gateway

[ Why it matters ]Priority signals

• Critical severity: CVSS 9.4

[ Description ]Official description

Kiteworks Email Protection Gateway did not sufficiently restrict which account a certificate could be assigned to. This could allow an attacker to associate a certificate with another user's account, affecting the confidentiality and integrity of that account's encrypted mail and, where certificate-based login is enabled, potentially permitting unauthorized access to the account.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• NCSC-NL8 Oct 2026NCSC-2026-0408

  Vulnerabilities fixed in Kiteworks Translated from Dutch

  Probability/damage M/HCVE-2026-102089CVE-2026-102090CVE-2026-102091+58 more CVEs
• BSI CERT-Bund30 Sep 2026WID-SEC-2026-3695

  Kiteworks: Multiple vulnerabilities Translated from German

  CVE-2026-102100CVE-2026-102144CVE-2026-102117+58 more CVEs

[ References ]References

• github.com/kiteworks/security-advisories/security/advisories/GHSA-c9w5-4frw-7wqqVendor Advisory
• raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/VA/white/2026/va-26-274-01.jsonBroken Link