Dogtag PKI: Authentication bypass in EST fullcmc enrollment allows rogue certificates
Summary
A flaw in the EST subsystem of Dogtag PKI (pki-core), the certificate authority software in Red Hat Certificate System, lets an authenticated EST user obtain CA-signed certificates with arbitrary subject names. The CMCAuthForEST plugin fails open for fullcmc enrollment requests sent via HTTP Basic authentication without an end-user TLS client certificate, so downstream checks treat the request as agent-privileged. Exploitation requires EST to be enabled and reachable with Basic authentication; the CVSS score is 8.1 (High).
Affected
- Red Hat Certificate System 10 (default: affected, per CVE record)
- Red Hat Certificate System 11 (default: affected, per CVE record)
- Red Hat Certificate System 9 and Red Hat Enterprise Linux 6 to 10 (default: unaffected, per CVE record; the record contains conflicting entries, so verify on the Red Hat page)
Fixed in
Unknown. No vendor-confirmed fixed version was found at the time of research. Treat as unpatched until Red Hat publishes an advisory naming CVE-2026-104988.
Workaround
- Disable Basic authentication for all users, as recommended by Red Hat: remove the field "UserPasswords" from the user entries in the EST DS server.
- Restrict network access to EST endpoints to known clients (recommended practice, not vendor guidance).
Exploitation
- Not known to be exploited in the wild. CISA SSVC assessment: exploitation none, automatable no, technical impact total.
- No public proof of concept found at the time of research.
Our recommendation
- Check whether Dogtag PKI or Red Hat Certificate System is in use and whether the EST subsystem is enabled and reachable.
- If EST is used, disable Basic authentication for EST users and restrict access to known clients now.
- Review certificates issued via EST since 2 October 2026 for unexpected subject names.
- Apply the vendor patch as soon as Red Hat publishes it and monitor the Red Hat CVE page for updates.
- No action needed if you do not run Dogtag PKI or Red Hat Certificate System with EST.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Red Hat CVE page CVE-2026-104988 access.redhat.com
- Red Hat Bugzilla 2545316 bugzilla.redhat.com
- Ubuntu CVE tracker CVE-2026-104988 ubuntu.com
- VulDB CVE-2026-104988 vuldb.com
- VulDB vulnerability 413213 vuldb.com
- TheHackerWire CVE-2026-104988 www.thehackerwire.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 1 Nov 2026, 20:57.
Original description (NVD)
A flaw was found in Dogtag PKI (pki-core). The CMCAuthForEST authentication plugin fails open when an EST fullcmc enrollment request is submitted via BasicAuth without an end-user TLS client certificate. The SSL_CLIENT_CERT session attribute retains the EST subsystem's agent certificate, which causes downstream authorization checks to treat the request as agent-privileged. An authenticated EST user can exploit this to obtain CA-signed certificates with arbitrary subject names.
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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