Information disclosure in Free5gc Udr
CVE-2026-27643
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 1.4.1, the NEF component reliably leaks internal parsing error details (e.g., invalid character 'n' after top-level value) to remote clients, which can aid attackers in service fingerprinting. All deployments of free5GC using the Nnef_PfdManagement service may be affected. free5gc/udr pull request 56 contains a patch for the issue. There is no direct workaround at the application level. The recommendation is to apply the provided patch.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.004 (36.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 36.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.002
Affected products
- Free5gc Udr — versions <= 1.4.1
Weakness classification (CWE)
References
- github.com/free5gc/free5gc/security/advisories/GHSA-6468-f87j-6g82 (Patch, Vendor Advisory)
- github.com/free5gc/free5gc/issues/753 (Exploit, Patch, Issue Tracking, Vendor Advisory)
- github.com/free5gc/udr/pull/56 (Patch, Issue Tracking)
- github.com/free5gc/udr/commit/754d23b03755ad59077ed529ce3b971e477080c4 (Patch)
Frequently asked questions
- What is CVE-2026-27643?
- CVE-2026-27643 is a medium-severity vulnerability in Free5gc Udr, classified under Generation of Error Message Containing Sensitive Information. CVSS score: 5.3/10. Published 2026-02-24.
- How severe is CVE-2026-27643?
- Medium severity. CVSS v3 base score is 5.3 out of 10.