CVE-2026-18369: Red Hat Certificate System 10

Medium severity, CVSS 5.8. EPSS: 0.2% chance of exploitation in the next 30 days.

A flaw was found in Dogtag PKI's ACME responder where the HTTP-01 challenge validator accepts IP address literals as dns identifiers and follows HTTP redirects without validating that the target is a public address. An unauthenticated ACME account holder can exploit this to perform server-side request forgery (SSRF), making the Dogtag server send HTTP GET requests to internal network services. With the InMemory database backend, the response body of internal targets is disclosed to the attacker through the ACME challenge error.

Affected products

• Red Hat Red Hat Certificate System 10
• Red Hat Red Hat Certificate System 10.4 Eus For Rhel-8: before 8060020260814202723.07fb4edf (fixed in 8060020260814202723.07fb4edf)
• Red Hat Red Hat Certificate System 11
• Red Hat Red Hat Certificate System 9
• Red Hat Red Hat Enterprise Linux 10
• Red Hat Red Hat Enterprise Linux 6
• Red Hat Red Hat Enterprise Linux 7
• Red Hat Red Hat Enterprise Linux 8
• Red Hat Red Hat Enterprise Linux 9

Published 2026-07-30. Last modified 2026-09-14.