Auth bypass in Free5gc
CVE-2026-44321
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…
Vulnerability class: Broken Authentication
EPSS: 0.001 (16.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Free5gc — versions < 4.2.2
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
- security-advisories@github.com (Exploit, x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (Patch, x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (Patch, x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-44321?
- CVE-2026-44321 is a high-severity vulnerability in Free5gc, classified under Missing Authentication for Critical Function. CVSS score: 7.5/10. Published 2026-05-27.
- How severe is CVE-2026-44321?
- High severity. CVSS v3 base score is 7.5 out of 10.