Summary
Canonical LXD Project Existence Determination Through Error Handling in Image Get Function
Impact
The LXD /1.0/images endpoint is implemented as an AllowUntrusted API that requires no authentication, making it accessible to users without accounts. This API allows determining project existence through differences in HTTP status codes when accessed with the project parameter.
https://github.com/canonical/lxd/blob/43d5189564d27f6161b430ed258c8b56603c2759/lxd/images.go#L63-L69
This configuration allows access without authentication:
This API returns a 404 error when accessing existing projects and a 403 error when accessing non-existent projects, allowing confirmation of project existence through this difference.
The problematic implementation is shown below.
First, in the error handling implementation of the imagesGet function below, project existence is checked within the projectutils.ImageProject function, and the err returned by the ImageProject function is directly returned to the user.
https://github.com/canonical/lxd/blob/43d5189564d27f6161b430ed258c8b56603c2759/lxd/i mages.go#L1781-L1788
When the project doesn't exist, the error is 404 (http.StatusNotFound), which is
returned to the user:
On the other hand, when the project exists but the user lacks viewing permissions, the imagesGet function returns 403 (response.Forbidden):
CVE-2025-54291 has a CVSS score of 5.3 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (5.21.4, 6.5, 0.0.0-20250827065555-0494f5d47e41); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
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. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
| LXD Series | Status |
|---|---|
| 6 | Fixed in LXD 6.5 |
| 5.21 | Fixed in LXD 5.21.4 |
| 5.0 | Ignored - Not critical |
| 4.0 | Ignored - EOL and not critical |
Frequently Asked Questions
- What is CVE-2025-54291? CVE-2025-54291 is a medium-severity security vulnerability in github.com/canonical/lxd (go), affecting versions >= 4.0, < 5.21.4. It is fixed in 5.21.4, 6.5, 0.0.0-20250827065555-0494f5d47e41.
- How severe is CVE-2025-54291? CVE-2025-54291 has a CVSS score of 5.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of github.com/canonical/lxd are affected by CVE-2025-54291? github.com/canonical/lxd (go) versions >= 4.0, < 5.21.4 is affected.
- Is there a fix for CVE-2025-54291? Yes. CVE-2025-54291 is fixed in 5.21.4, 6.5, 0.0.0-20250827065555-0494f5d47e41. Upgrade to this version or later.
- Is CVE-2025-54291 exploitable, and should I be worried? Whether CVE-2025-54291 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
- What actually determines whether CVE-2025-54291 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.
- How do I fix CVE-2025-54291?
- Upgrade
github.com/canonical/lxdto 5.21.4 or later - Upgrade
github.com/canonical/lxdto 6.5 or later - Upgrade
github.com/canonical/lxdto 0.0.0-20250827065555-0494f5d47e41 or later
- Upgrade