CVE-2026-44321 — Security Box Score

CVE · referencelatest edition

Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-44321HIGH

free5GC: SMF UPI POST /upi/v1/upNodesLinks exits the SMF process on overlapping UE pools (unauthenticated, reachable Fatalf)

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  N  N  H    7.5   .0036   29.7     —

AFFECTED
  Product  Versions   Fixed
  free5gc  < 4.2.2 –  —

TIMELINE
  May 5   Reserved by GitHub_M
  May 27  EXPLOIT PUBLISHED — CVE-2026-44321 (free5gc). Public exploit reference added.
  May 27  Published (CNA: GitHub_M)

CWE-306, CWE-617, CWE-862 · CNA: GitHub_M · CVSS v3.1 · 4 references · NVD status: Analyzed

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
May 5, 2026	Reserved	Reserved by GitHub_M
May 27, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-44321 (free5gc). Public exploit reference added.
May 27, 2026	Published	Published (CNA: GitHub_M)

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
free5gc	free5gc	—	< 4.2.2	—

Weaknesses

CWE-306 · CWE-617 · CWE-862

References (4)

https://github.com/free5gc/free5gc/issues/906 [Exploit, Issue Tracking]
https://github.com/free5gc/free5gc/security/advisories/GHSA-44qj-cghf-9p97 [Exploit, Vendor Advisory]
https://github.com/free5gc/smf/commit/e0974e07ddab44a67d36a563cca383b2449e33e5 [Patch]
https://github.com/free5gc/smf/pull/203 [Issue Tracking, Patch]

Authoritative record: CVE-2026-44321 at cve.org

Vendors: free5gc

Weaknesses: CWE-306 · CWE-617 · CWE-862

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-44321 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.