Red Hat Certificate System/Enterprise Linux ACME responder web.xml improper authorization

Summaryinfo

A vulnerability was found in Red Hat Certificate System and Enterprise Linux. It has been rated as very critical. This vulnerability affects unknown code of the file web.xml of the component ACME responder. Performing a manipulation results in improper authorization. This vulnerability is cataloged as CVE-2026-18047. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability classified as very critical has been found in Red Hat Certificate System and Enterprise Linux (version unknown). This affects an unknown function of the file web.xml of the component ACME responder. The manipulation with an unknown input leads to a improper authorization vulnerability. CWE is classifying the issue as CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

A flaw was found in Dogtag PKI's ACME responder where the web.xml security constraints use exact URL pattern matching for admin-only enable/disable endpoints. By appending a trailing slash to the URL, an unauthenticated attacker can bypass the Tomcat authentication constraint while RESTEasy still routes the request to the handler, allowing unauthorized toggling of the ACME service state including persistent denial of service.

It is possible to read the advisory at access.redhat.com. This vulnerability is uniquely identified as CVE-2026-18047 since 07/28/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 07/28/2026). The attack technique deployed by this issue is T1548.002 according to MITRE ATT&CK.

By approaching the search of inurl:web.xml it is possible to find vulnerable targets with Google Hacking.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Red Hat

Name

• Certificate System
• Enterprise Linux

License

• open-source

Website

• Vendor: https://www.redhat.com/

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