Kiteworks Email Protection Gateway: Server-Side Request Forgery
Summary
Kiteworks Email Protection Gateway before 9.5.0 contains a Server-Side Request Forgery (SSRF) flaw in its online certificate status check for inbound messages. A remote, unauthenticated attacker can cause the gateway to send crafted requests to internal or unintended network destinations. Depending on the services reachable from the gateway, this can disclose sensitive internal information or disrupt gateway operation. The CVSS score is 9.1 (critical).
Affected
- Kiteworks Email Protection Gateway versions before 9.5.0
Fixed in
- Version 9.5.0 or later
Workaround
Unknown. The vendor has published no workaround. As a compensating control, restrict the gateway's outbound connections to what it needs and block its access to internal networks.
Exploitation
- No exploitation in the wild found at the time of research.
- No public proof-of-concept found.
- CISA KEV status not confirmed.
Our recommendation
- Check whether the environment runs self-managed Email Protection Gateway and confirm the installed version.
- Update self-managed installations to 9.5.0 or later; the vendor's current release is the preferred target.
- For vendor-hosted instances, ask the provider to confirm patch status.
- Until patched, restrict the gateway's outbound connections and block access to internal networks.
- Monitor gateway logs for unusual outbound requests.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Kiteworks GitHub Security Advisory GHSA-mqw3-m87w-4fx4 github.com
- CISA CSAF advisory va-26-274-01 raw.githubusercontent.com
- OpenCVE: CVE-2026-102104 app.opencve.io
- VulDB: CVE-2026-102104 vuldb.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 31 Oct 2026, 07:52.
Original description (NVD)
Kiteworks Email Protection Gateway before version 9.5.0 is vulnerable to Server-Side Request Forgery (SSRF). A server-side request forgery (SSRF) weakness in Kiteworks Email Protection Gateway could allow a remote, unauthenticated attacker to induce the gateway to issue crafted requests to internal or otherwise unintended network destinations. The requests are triggered while the gateway performs an online certificate status check for an inbound message. Depending on the services reachable from the gateway, this could disclose sensitive internal information or disrupt gateway operation.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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