Fava vulnerable to Reflected Cross-site ScriptingGHSA-q8hg-3vqv-f8v3
MEDIUMFix: beancount/fava@dccfb6aGHSA-q8hg-3vqv-f8v3 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in fava. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for fava — see the affected versions and patch details below.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
favaReal-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
Cross-site Scripting (XSS) - Reflected in GitHub repository beancount/fava prior to 1.22.2.
The query_string parameter of Fava is vulnerable to reflected cross-site scripting, for which a attacker can modify any information that the user is able to modify. This issue is fixed in version 1.22.2.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | fava | all versions | 1.22.2pip install --upgrade 'fava==1.22.2' |
Affected Products
favafava_projectResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for fava, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update fava to 1.22.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-q8hg-3vqv-f8v3 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is GHSA-q8hg-3vqv-f8v3 in your dependencies?
Find it across PyPI, including transitive dependencies.