PatchTheCVECVE-2026-40248: free5GC is an open-source implementation of the 5G core network
CVE-2026-40248 is a high-severity flaw (CVSS 7.5) affecting free5gc. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
free5GC is an open-source implementation of the 5G core network. In versions 4.2.1 and below of the UDR service, the handler for creating or updating 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 created or overwritten regardless. An unauthenticated attacker with access to
Why this priority
- High severity
- Public exploit reference
- Remotely exploitable, no login, no user action
A fixed release or distro patch exists.
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-40248?
free5gc: upgrade to newer than 4.2.1. Exact commands for each OS are on this page.
Is CVE-2026-40248 being exploited?
CVE-2026-40248 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-40248 affect?
CVE-2026-40248 affects free5gc. Severity is high (CVSS 7.5). free5GC is an open-source implementation of the 5G core network. In versions 4.2.1 and below of the UDR service, the handler for creating or updating Traffic Influence Subscriptions checks whether the influenceId path segment equals subs-to
How urgent is CVE-2026-40248?
Priority 45/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action
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