CVE-2026-44321

HIGH EPSS 28.3%
Published May 27, 20261mo ago · Modified Jun 17, 20262w ago
7.5 CVSS 3.1
High
Find Similar
Published May 27, 2026 1mo ago
Last Modified Jun 17, 2026 2w ago

Description

free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's SMF mounts the UPI management route group without inbound OAuth2 middleware. The POST /upi/v1/upNodesLinks create-or-update handler accepts attacker-controlled JSON and passes it directly into UpNodesFromConfiguration(), which calls logger.InitLog.Fatalf(...) on several validation failures. One confirmed path is the UE-IP-pool overlap check: a single unauthenticated POST that adds a new UPF whose pool overlaps an existing UPF terminates the entire SMF process (docker ps shows Exited (1)), not just the goroutine. This vulnerability is fixed in 4.2.2.

CVSS Details

Base Score
7.5
Exploitability
3.9
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
28.3% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 3

CWE-306 Missing Authentication for Critical Function Authentication
CWE-617
CWE-862 Missing Authorization Authorization

Affected Products 1

VendorProductVersionRange
free5gcfree5gc* <4.2.2

References 4

  • github.com https://github.com/free5gc/free5gc/issues/906
    ExploitIssue Tracking
  • github.com https://github.com/free5gc/free5gc/security/advisories/GHSA-44qj-cghf-9p97
    ExploitVendor Advisory
  • github.com https://github.com/free5gc/smf/commit/e0974e07ddab44a67d36a563cca383b2449e33e5
    Patch
  • github.com https://github.com/free5gc/smf/pull/203
    Issue TrackingPatch

Remediation

  • github.com https://github.com/free5gc/smf/commit/e0974e07ddab44a67d36a563cca383b2449e33e5
    Patch
  • github.com https://github.com/free5gc/smf/pull/203
    Issue TrackingPatch