CVE-2026-39845 is a medium-severity (CVSS 4.1) Server-Side Request Forgery (SSRF) vulnerability in weblate. A fix is available for weblate — see the affected versions and patch details below.
Weblate: SSRF via the webhook add-on using unprotected fetch_url()
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-2026-39845.
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
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
Weblate is a web based localization tool. In versions prior to 5.17, the webhook add-on did not utilize existing SSRF protections. This issue has been fixed in version 5.17. If developers are unable to update immediately, they can disable the webhook add-on as a workaround.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | weblate | all versions | 5.17pip install --upgrade 'weblate==5.17' |
Affected Products
weblateweblateDetection & 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 5.17 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-39845 is resolved across your whole dependency graph.
Workarounds
Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.
Frequently Asked Questions
Is CVE-2026-39845 in your dependencies?
Find it across PyPI, including transitive dependencies.