CVE-2026-23517

Fleet has an Access Control vulnerability in debug/pprof endpoints

A broken access control issue in Fleet allowed authenticated users to access debug and profiling endpoints regardless of role. As a result, low-privilege users could view internal server diagnostics and trigger resource-intensive profiling operations.

Workarounds

If an immediate upgrade is not possible, users should put the debug/pprof endpoints behind an IP allowlist.

For more information

If you have any questions or comments about this advisory:

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Credits

We thank @secfox-ai for responsibly reporting this issue.

Fleet’s debug/pprof endpoints are accessible to any authenticated user regardless of role, including the lowest-privilege “Observer” role. This allows low-privilege users to access sensitive server internals, including runtime profiling data and in-memory application state, and to trigger CPU-intensive profiling operations that could lead to denial of service.

The application does not perform an authorization check before performing a sensitive operation. Typical impact: unauthorized access to restricted functionality or data.

Kodem intelligence

Already deployed Kodem?

• 4.78.3
• 4.77.1
• 4.76.2
• 4.75.2
• 4.53.3

1. What is CVE-2026-23517? CVE-2026-23517 is a high-severity missing authorization vulnerability in github.com/fleetdm/fleet (go), affecting versions >= 4.78.0, < 4.78.3. It is fixed in 4.78.3, 4.77.1, 4.76.2, 4.75.2, 4.78.3-0.20260112221730-5c030e32a3a9. The application does not perform an authorization check before performing a sensitive operation.
2. Which packages are affected by CVE-2026-23517?
   • github.com/fleetdm/fleet (go) (versions >= 4.78.0, < 4.78.3)
   • github.com/fleetdm/fleet/v4 (go) (versions < 4.78.3-0.20260112221730-5c030e32a3a9)
3. Is there a fix for CVE-2026-23517? Yes. CVE-2026-23517 is fixed in 4.78.3, 4.77.1, 4.76.2, 4.75.2, 4.78.3-0.20260112221730-5c030e32a3a9. Upgrade to this version or later.
4. Is CVE-2026-23517 exploitable, and should I be worried? Whether CVE-2026-23517 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
5. What actually determines whether CVE-2026-23517 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
6. How do I fix CVE-2026-23517?
   • Upgrade github.com/fleetdm/fleet to 4.78.3 or later
   • Upgrade github.com/fleetdm/fleet to 4.77.1 or later
   • Upgrade github.com/fleetdm/fleet to 4.76.2 or later
   • Upgrade github.com/fleetdm/fleet to 4.75.2 or later
   • Upgrade github.com/fleetdm/fleet/v4 to 4.78.3-0.20260112221730-5c030e32a3a9 or later

Other vulnerabilities in github.com/fleetdm/fleet