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TI-2026-22024 Aliases CVE-2026-27642

free5GC has Improper Input Validation in UDM UEAU Service

Priority LOW 36CWE-20Published · Updated

Key facts

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

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

free5gc UDM provides Unified Data Management (UDM) for free5GC, an open-source project for 5th generation (5G) mobile core networks. In versions up to and including 1.4.1, remote attackers can inject control characters (e.g., %00) into the supi parameter, triggering internal URL parsing errors (net/url: invalid control character). This exposes system-level error details and can be used for service fingerprinting. All deployments of free5GC using the UDM Nudm_UEAU service may be affected. free5gc/udm pull request 75 contains a fix for the issue. No direct workaround is available at the application level. Applying the official patch is recommended.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0057 47th 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
free5gcudmup to 1.4.1—No fix listedCNA
  • udm Vendorfree5gc Affected up to 1.4.1 Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:free5gc:udm:*:*:*:*:*:go:*:*up to 1.4.1Vulnerablefree5gc
  • cpe:2.3:a:free5gc:udm:*:*:*:*:*: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-2026-27642
  2. 2026-10-13 EPSS moved to the 50th–90th percentile
  3. 2026-10-25 EPSS moved to the below the 50th percentile

References

Exploit 1

Patch 2

Advisory 1

  • TI-2026-25617 free5GC UDM incorrectly returns 500 for empty supi path parameter in PATCH sdm-subscriptions reques CVSS 4.0HIGH 8.7
  • TI-2026-25506 free5GC UDM DataChangeNotification Procedure Panic Due to Nil Pointer Dereference CVSS 4.0HIGH 8.7
  • TI-2026-25507 free5GC UDM incorrectly returns 500 for empty supi path parameter in DELETE sdm-subscriptions request CVSS 4.0MEDIUM 6.9
  • TI-2026-25616 free5GC UDM vulnerable to null byte injection in URL path parameters causing 500 Internal Server Error CVSS 4.0HIGH 8.7
  • TI-2025-42704 free5GC has Null Pointer Dereference in UDM, Leading to Service Panic CVSS 4.0MEDIUM 6.6
  • TI-2025-42703 free5GC has Improper Input Validation in UDM, Leading to Information Exposure CVSS 4.0MEDIUM 6.6
See all 8 →

Sources

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