Quick answers
- Is CVE-2026-30058 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-30058 being exploited in the wild.
- How severe is CVE-2026-30058?
- High severity, with a CVSS score of 7.5, published 27 August 2026.
- Which products and versions are affected?
- free5GC v4.0.1.
- Is there a fix for CVE-2026-30058?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-30058 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-30058?
- Check whether you run free5GC at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The vulnerability is an improper input validation flaw in the ModifyAMFEventSubscriptionProcedure function within the HTTPModifySubscription handler. The code attempts to slice a JSON Patch path string at a fixed position (characters 11 onwards) without first validating that the path is at least 11 characters long. When a PATCH request is sent with a path shorter than 11 characters (e.g., "/a"), the slice operation causes a runtime panic ("slice bounds out of range"), crashing the AMF process. The vulnerability is reachable over the network via the /namf-evts/v1/subscriptions endpoint without requiring authentication. An attacker can repeatedly trigger this crash to cause a denial of service, preventing legitimate 5G network operations.
Affected products
- free5gc free5gc v4.0.1
Timeline
- 2026-01-01: disclosed: Issue opened on GitHub
- 2026-08-27: advisory: CVE-2026-30058 published