GHSA-75vq-qvhr-7ffr
MEDIUMUmbraco Delivery API allows for cached requests to be returned with an invalid API key
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.
Blast Radius
Umbraco.Cms.Api.Delivery.NETUmbraco.Cms.Api.Delivery.NETUmbraco.Cms.Api.DeliveryReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.
Description
Impact
Umbraco's content delivery API can be restricted from public access such that an API key must be provided in a header to authorize the request.
It's also possible to configure output caching, such that the delivery API outputs will be cached for a period of time, improving performance.
There's an issue when these two things are used together though in that the caching doesn't vary by the header that contains the API key. As such it's possible for a user without a valid API key to retrieve a response for a given path and query if it has recently been requested and cached by request with a valid key.
Patches
Patches will be available in 13.9.3, 15.4.4 and 16.1.1.
Workarounds
Workaround is to remove or reduce the time period of the output caching or to provide other restrictions to access the delivery API such as by IP.
References
Content delivery API documentation: https://docs.umbraco.com/umbraco-cms/reference/content-delivery-api
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| .NETNuGet | Umbraco.Cms.Api.Delivery | ≥ 13.0.0&&< 13.9.3 | 13.9.3 |
| .NETNuGet | Umbraco.Cms.Api.Delivery | ≥ 15.0.0&&< 15.4.4 | 15.4.4 |
| .NETNuGet | Umbraco.Cms.Api.Delivery | ≥ 16.0.0&&< 16.1.1 | 16.1.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Umbraco.Cms.Api.Delivery. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update Umbraco.Cms.Api.Delivery to 13.9.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-75vq-qvhr-7ffr 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 pinpoints whether GHSA-75vq-qvhr-7ffr is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-75vq-qvhr-7ffr. 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-75vq-qvhr-7ffr in your dependencies?
O3 detects GHSA-75vq-qvhr-7ffr across NuGet dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.