# CVE-2026-102103: Kiteworks Email Protection Gateway SSRF in certificate revocation list handling

Source: https://junglewise.ai/threats/cve-2026-102103-kiteworks-email-protection-gateway-before-version-9-5-0-is  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-30. Updated: 2026-09-30  
License: CC BY 4.0 with a link back

CVE-2026-102103 · Severity: critical · CVSS 9.1 · Published 2026-09-30

Kiteworks Email Protection Gateway, a security appliance that controls inbound and outbound email, contains a server-side request forgery (SSRF) flaw that allows remote attackers without credentials to trick the gateway into making requests to unintended internal systems. An attacker can exploit this through crafted inbound messages that trigger certificate revocation list retrieval, potentially exposing sensitive internal information or disrupting email operations.

Technologies: [Kiteworks Email Protection Gateway](https://junglewise.ai/threats/technologies/email-protection-gateway). Vendors: [Kiteworks](https://junglewise.ai/threats/vendors/kiteworks).

## Quick answers

**Is CVE-2026-102103 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-102103 being exploited in the wild.

**How severe is CVE-2026-102103?** Critical severity, with a CVSS score of 9.1, published 30 September 2026.

**Which products and versions are affected?** Kiteworks Email Protection Gateway before 9.5.0.

**Is there a fix for CVE-2026-102103?** A patch was published on 2026-09-30: version 9.5.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-102103 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-102103?** Check whether you run Kiteworks Email Protection Gateway at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The gateway fails to properly validate URLs when retrieving certificate revocation lists during inbound message processing, allowing an unauthenticated remote attacker to induce the server to issue requests to arbitrary internal or external destinations via SSRF. The vulnerability requires no user interaction and can result in information disclosure (high confidentiality impact) or denial of service (high availability impact) depending on backend services accessible from the gateway.

## Affected products

- Kiteworks Email Protection Gateway before 9.5.0

## Timeline

- 2026-09-30: disclosed
- 2026-09-30: patched: version 9.5.0

## References

- [https://github.com/kiteworks/security-advisories/security/advisories/GHSA-p435-6c3j-4gh5](https://github.com/kiteworks/security-advisories/security/advisories/GHSA-p435-6c3j-4gh5)
- [https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/VA/white/2026/va-26-274-01.json](https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/VA/white/2026/va-26-274-01.json)

## Related threats

- [Kiteworks Email Protection Gateway improper access control on certificate assignment](https://junglewise.ai/threats/cve-2026-102149-kiteworks-email-protection-gateway-did-not-sufficiently-restrict)
- [Kiteworks Email Protection Gateway arbitrary file write via template injection](https://junglewise.ai/threats/cve-2026-102146-an-authenticated-email-protection-gateway-administrator-holding)
- [Kiteworks Email Protection Gateway resource exhaustion](https://junglewise.ai/threats/cve-2026-102144-a-resource-exhaustion-vulnerability-in-kiteworks-email)
- [Kiteworks Email Protection Gateway unauthenticated file upload](https://junglewise.ai/threats/cve-2026-102143-an-unauthenticated-attacker-could-cause-a-file-with-attacker)
- [Kiteworks Email Protection Gateway authorization bypass in large file exchange](https://junglewise.ai/threats/cve-2026-102139-an-authorization-check-in-the-large-file-exchange-feature-of)