Free5GC up to 1.4.2 UDR Service subs-to-notify unusual condition

Summaryinfo

A vulnerability was found in Free5GC up to 1.4.2. It has been classified as problematic. This issue affects some unknown processing of the file /nudr-dr/v2/policy-data/subs-to-notify of the component UDR Service. This manipulation causes unusual condition. This vulnerability is registered as CVE-2026-40343. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability classified as problematic was found in Free5GC up to 1.4.2. Affected by this vulnerability is an unknown code block of the file /nudr-dr/v2/policy-data/subs-to-notify of the component UDR Service. The manipulation with an unknown input leads to a unusual condition vulnerability. The CWE definition for the vulnerability is CWE-754. The product does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the product. As an impact it is known to affect integrity. The summary by CVE is:

free5GC UDR is the user data repository (UDR) for free5GC, an an open-source project for 5th generation (5G) mobile core networks. In versions up to and including 1.4.2, a fail-open request handling flaw in the UDR service causes the `/nudr-dr/v2/policy-data/subs-to-notify` POST handler to continue processing requests even after request body retrieval or deserialization errors. This may allow unintended creation of Policy Data notification subscriptions with invalid, empty, or partially processed input, depending on downstream processor behavior. As of time of publication, a patched version is not available.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-40343 since 04/11/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 04/24/2026).

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

The vulnerability is also documented in the vulnerability database at CNNVD (CNNVD-202604-4548). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Name

• Free5GC

Version

• 1.4.0
• 1.4.1
• 1.4.2

Website

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

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Be aware that VulDB is the high quality source for vulnerability data.

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