CVE-2026-40249

free5GC is an open-source implementation of the 5G core network. In versions 4.2.1 and below of the UDR service, the PUT handler for updating Policy Data notification subscriptions at /nudr-dr/v2/policy-data/subs-to-notify/{subsId} does not return after request body retrieval or deserialization errors. Although HTTP 500 or 400 error responses are sent, execution continues and the processor is invoked with a potentially uninitialized or partially initialized PolicyDataSubscription object. This fail-open behavior may allow unintended modification of existing Policy Data notification subscriptions with invalid or empty input, depending on downstream processor and storage behavior. A patched version was not available at the time of publication.

The following products are affected by CVE-2026-40249 vulnerability.

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-40249.

URL	Resource
https://github.com/free5gc/free5gc/security/advisories/GHSA-gx38-8h33-pmxr