CVE-2026-40246: free5gc UDR improper path validation allows unauthenticated deletion of Traffic Influence Subscriptions

Vulnerability summary

CVE-2026-40246 is a high (CVSS 8.7) Improper Authorization vulnerability in free5gc. EPSS estimates a 0.45% chance of exploitation in the next 30 days, higher than 38.1% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 16-04-2026
   PublishedVulnerability first disclosed.
2. 18-04-2026
   Last modifiedVulnerability information updated.

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.

• CWE-285Improper AuthorizationThe product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.