Vulnerability · Published Feb 24, 2026 · Assigned by GitHub_M

CVE-2026-27643free5GC has improper error handling in NEF with information exposure

Medium 6.6

In plain English

A medium-severity security flaw in udr from free5gc. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 24% of all known vulnerabilities).

Severity (CVSS 4.0)6.6Medium

Exploit odds (30 days)0.3%top 75.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
free5gc	udr	<= 1.4.1

Weakness: CWE-209 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U

References

https://github.com/free5gc/free5gc/security/advisories/GHSA-6468-f87j-6g82 x_refsource_CONFIRM
https://github.com/free5gc/free5gc/issues/753 x_refsource_MISC
https://github.com/free5gc/udr/pull/56 x_refsource_MISC
https://github.com/free5gc/udr/commit/754d23b03755ad59077ed529ce3b971e477080c4 x_refsource_MISC