CVE-2026-44328

free5GC: SMF UPI DELETE /upi/v1/upNodesLinks/{ref} panics on AN-node deletion via nil UPF dereference; unauthenticated, state-mutating

HIGH
8.2
CVSS Score
Published: May 27, 2026 at 03:39 PM UTC
Updated: October 14, 2026 at 08:10 PM UTC
1 product affected across 1 vendorFREE5GC

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Severity
HIGH8.2
Exploit prediction
EPSS 0.3%
SSVC
PoC

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 4.2.2
Affected range stops below 4.2.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (4)

x_refsource_CONFIRMExploitVendor Advisory
Source: cverecord
https://github.com/free5gc/free5gc/security/advisories/GHSA-p9mg-74mg-cwwr
x_refsource_MISCExploitIssue Tracking
Source: cverecord
https://github.com/free5gc/free5gc/issues/905
x_refsource_MISCIssue TrackingPatch
Source: cverecord
https://github.com/free5gc/smf/pull/199

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.2HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
LOW
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-306CWE-476CWE-862

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