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.
free5GC: NEF nnef-callback route group is unauthenticated; forged callback requests are accepted into the processing path
AV AC PR UI S C I A CVSS EPSS %ile KEV
N L N N U L L L 7.3 .0024 15.5 —
AFFECTED
Product Versions Fixed
free5gc < 4.2.2 – —
TIMELINE
May 5 Reserved by GitHub_M
May 27 EXPLOIT PUBLISHED — CVE-2026-44320 (free5gc). Public exploit reference added.
May 27 Published (CNA: GitHub_M)
Description
free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's NEF mounts the nnef-callback route group without inbound OAuth2/bearer-token authorization. A forged or arbitrary bearer token (e.g. Authorization: Bearer not-a-real-token) is enough to reach the SMF-callback handler -- the callback body is parsed and dispatched into NEF business logic instead of being rejected at the auth boundary. Same root cause as the other NEF SBI findings: the route group is mounted without any inbound auth middleware. NEF does not authenticate the producer NF identity before processing callback content; if an attacker can guess or obtain a valid NotifId, this missing auth boundary lets forged callbacks act on real subscription state. The route group is also reachable even when the runtime ServiceList does not declare it (it lists only nnef-pfdmanagement and nnef-oam). 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-2026-44320 (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 | — |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-44320 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.