Free5GC up to 1.4.2 UDR Service improper authorization

Summaryinfo

A vulnerability, which was classified as critical, has been found in Free5GC up to 1.4.2. This affects an unknown function of the component UDR Service. Performing a manipulation results in improper authorization. This vulnerability is identified as CVE-2026-40246. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in Free5GC up to 1.4.2. It has been classified as critical. This affects an unknown functionality of the component UDR Service. The manipulation with an unknown input leads to a improper authorization vulnerability. CWE is classifying the issue as CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. This is going to have an impact on integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-40246 since 04/10/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 04/17/2026). MITRE ATT&CK project uses the attack technique T1548.002 for this issue.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Name

• Free5GC

Version

• 1.4.0
• 1.4.1
• 1.4.2

Website

• Product: https://github.com/free5gc/free5gc/

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