CVE-2024-39303 is a medium-severity (CVSS 4.4) CWE-73 vulnerability in weblate. A fix is available for weblate — see the affected versions and patch details below.
Weblate vulnerabler to improper sanitization of project backups
Exploitation Status
No confirmed exploitation observed yet
- 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 CVE-2024-39303.
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
CVE-2024-39303 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 378,567 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
weblateReal-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
Impact
Weblate didn't correctly validate filenames when restoring project backup. It may be possible to gain unauthorized access to files on the server using a crafted ZIP file.
Patches
This issue has been addressed in Weblate 5.6.2 via https://github.com/WeblateOrg/weblate/commit/b6a7eace155fa0feaf01b4ac36165a9c5e63bfdd.
Workarounds
Do not allow project creation to untrusted users.
References
Thanks to Bryan Cahill for bringing this issue to our attention.
For more information
If you have any questions or comments about this advisory:
- Open a topic in discussions
- Email us at [email protected]
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | weblate | ≥ 4.14&&< 5.6.2 | 5.6.2pip install --upgrade 'weblate==5.6.2' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for weblate, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update weblate to 5.6.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-39303 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 CVE-2024-39303 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2024-39303. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2024-39303 in your dependencies?
O3 Security finds CVE-2024-39303 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.