GHSA-hp6r-r9vc-q8wx is a medium-severity (CVSS 6.3) CWE-285 vulnerability in fastapi-sso. A fix is available for fastapi-sso — see the affected versions and patch details below.
FastAPI SSP is vulnerable to Cross-site Request Forgery (CSRF) through improper OAuth parameter validation
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for GHSA-hp6r-r9vc-q8wx.
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-hp6r-r9vc-q8wx 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 377,166 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
fastapi-ssoReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Versions of the package fastapi-sso before 0.19.0 are vulnerable to Cross-site Request Forgery (CSRF) due to the improper validation of the OAuth state parameter during the authentication callback. While the get_login_url method allows for state generation, it does not persist the state or bind it to the user's session. Consequently, the verify_and_process method accepts the state received in the query parameters without verifying it against a trusted local value. This allows a remote attacker to trick a victim into visiting a malicious callback URL, which can result in the attacker's account being linked to the victim's internal account.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | fastapi-sso | all versions | 0.19.0pip install --upgrade 'fastapi-sso==0.19.0' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for fastapi-sso, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update fastapi-sso to 0.19.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-hp6r-r9vc-q8wx 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-hp6r-r9vc-q8wx can be triaged on real exposure rather than presence alone.
Tailored to GHSA-hp6r-r9vc-q8wx. 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-hp6r-r9vc-q8wx in your dependencies?
O3 Security finds GHSA-hp6r-r9vc-q8wx across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.