CVE-2026-40246 free5gc UDR improper path validation allows unauthenticated deletion of Traffic Influence Subscriptions
Unauthenticated attackers can delete arbitrary Traffic Influence Subscriptions in free5GC UDR due to improper path validation logic.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-40246?
CVE-2026-40246 is a high-severity missing authorization vulnerability in free5gc, published on 16 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
free5GC is an open-source implementation of the 5G core network. In versions 1.4.2 and below of the UDR service, the handler for deleting Traffic Influence Subscriptions checks whether the influenceId path segment equals subs-to-notify, but does not return after sending the HTTP 404 response when validation fails. Execution continues and the subscription is deleted regardless. An unauthenticated attacker with access to the 5G Service Based Interface can delete arbitrary Traffic Influence Subscriptions by supplying any value for the influenceId path segment, while the API misleadingly returns a 404 Not Found response. A patched version was not available at the time of publication.
Weakness: CWE-285
Which versions are affected by CVE-2026-40246?
3 open source packages ship an affected version, including github.com/free5gc/udr. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/free5gc/udr Go | All versions | None |
github.com/free5gc/udr Go | All versions to 1.4.2 | None |
github.com/free5gc/udr Go | All versions to 1.4.2 | None |
Products include Free5gc Webconsole.
How do I fix CVE-2026-40246?
No fix published yet.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-40246 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-40246 exists.
Other vulnerabilities in free5gc
Sources
Also known as GHSA-g9cw-qwhf-24jp, GO-2026-5396.