# CVE-2026-18047: Dogtag-pki: pki-core: redhat-pki: pki: acme admin enable/disable endpoint authentication bypass via trailing slash

> Unauthenticated attackers can bypass authentication on ACME admin endpoints via trailing slash manipulation, allowing unauthorized service state changes and denial of service.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 28 Jul 2026
- **Updated:** 28 Jul 2026
- **Also known as:** DEBIAN-CVE-2026-18047, GHSA-5xgg-8pvj-x39g, UBUNTU-CVE-2026-18047

## What is CVE-2026-18047?

CVE-2026-18047 is a medium-severity authentication bypass vulnerability in Red Hat Certificate System 10, published on 28 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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.

Weakness: CWE-288 (Authentication Bypass Using an Alternate Path or Channel)

## Which versions are affected by CVE-2026-18047?


## How do I fix CVE-2026-18047?

No fix has been published for CVE-2026-18047 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-18047 being exploited?

There is no known exploitation of CVE-2026-18047 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-18047 and fix it if it is affected.

What it is: CVE-2026-18047 is a medium-severity authentication bypass vulnerability in Red Hat Certificate System 10, published on 28 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-18047 in the wild and no public exploit code.

Affected product: Red Hat Certificate System 10. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-18047/ (Markdown: https://insights.sbomify.com/CVE-2026-18047/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-18047
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-18047
- OSV: https://osv.dev/vulnerability/CVE-2026-18047

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-18047/
Summaries are generated and may contain mistakes; the official description above is the record.