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TI-2026-22025 Aliases CVE-2026-27643

free5GC has improper error handling in NEF with information exposure

Priority LOW 35CWE-209Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Information disclosure
Confidentiality · integrity · availability
High · None · None
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-209.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00313 24th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
free5gcudrup to 1.4.1—No fix listedCNA
  • udr Vendorfree5gc Affected up to 1.4.1 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:free5gc:udr:*:*:*:*:*:go:*:*up to 1.4.1Vulnerablefree5gc
  • cpe:2.3:a:free5gc:udr:*:*:*:*:*:go:*:* Versions up to 1.4.1 Vulnerable ·free5gc

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-27643

References

Exploit 1

Patch 3

  • TI-2026-29118 free5GC UDR: Fail-open handling in PolicyDataSubsToNotifyPost allows unintended subscription creation CVSS 4.0MEDIUM 6.9
  • TI-2025-42705 free5GC vulnerable to improper error handling in NEF with information exposure CVSS 4.0MEDIUM 6.6
  • TI-2025-42662 free5GC UDR's NEF incorrectly returns 500 for missing PFD data (UDR 404) in Nnef_PfdManagement GET request CVSS 4.0LOW 2.7

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences