Vulnerability · Published May 27, 2026 · Assigned by GitHub_M
CVE-2026-44328free5GC: SMF UPI DELETE /upi/v1/upNodesLinks/{ref} panics on AN-node deletion via nil UPF dereference; unauthenticated, state-mutating
High 8.2
In plain English
A high-severity missing authentication in free5gc from free5gc. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 26% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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. On top of that, the DELETE /upi/v1/upNodesLinks/{upNodeRef} handler unconditionally dereferences upNode.UPF after the type-guarded async release, even though AN-typed nodes are constructed without a UPF object. As a result, a single unauthenticated DELETE /upi/v1/upNodesLinks/gNB1 request crashes the handler with a nil-pointer panic AND mutates the in-memory user-plane topology before panicking (the UpNodeDelete(upNodeRef) line runs first). This is an unauthenticated, state-mutating panic-DoS sink that an off-path network attacker can trigger by name against any AN entry. This vulnerability is fixed in 4.2.2.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/free5gc/smf | 1.4.3 | GHSA-p9mg-74mg-cwwr |
| Go | github.com/free5gc/smf | 1.4.3 | GO-2026-5537 |
Affected products (as reported)
Weakness: CWE-306, CWE-476, CWE-862 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
References
- https://github.com/free5gc/free5gc/security/advisories/GHSA-p9mg-74mg-cwwr x_refsource_CONFIRM
- https://github.com/free5gc/free5gc/issues/905 x_refsource_MISC
- https://github.com/free5gc/smf/pull/199 x_refsource_MISC
- https://github.com/free5gc/smf/commit/b57bc48081c3d3a2f333d02eb78e4fd31a120deb x_refsource_MISC