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.
Fix
Patch, vendor advisory and mitigation references on NVD 4
- https://github.com/free5gc/free5gc/security/advisories/GHSA-p9mg-74mg-cwwr Exploit, Vendor Advisory
- https://github.com/free5gc/smf/commit/b57bc48081c3d3a2f333d02eb78e4fd31a120deb Patch
- https://github.com/free5gc/smf/pull/199 Issue Tracking, Patch
- https://github.com/free5gc/free5gc/security/advisories/GHSA-p9mg-74mg-cwwr Exploit, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 8.2 · free5gcNVD modified 2026-10-14 20:10
Affected (CPE criteria) 1
cpe:2.3:a:free5gc:free5gc:*:*:*:*:*:*:*:*
References 6
- https://github.com/free5gc/free5gc/issues/905 Exploit, Issue Tracking
- https://github.com/free5gc/free5gc/security/advisories/GHSA-p9mg-74mg-cwwr Exploit, Vendor Advisory
- https://github.com/free5gc/smf/commit/b57bc48081c3d3a2f333d02eb78e4fd31a120deb Patch
- https://github.com/free5gc/smf/pull/199 Issue Tracking, Patch
- https://github.com/free5gc/free5gc/issues/905 Exploit, Issue Tracking
- https://github.com/free5gc/free5gc/security/advisories/GHSA-p9mg-74mg-cwwr Exploit, Vendor Advisory