CVE-2026-44328

CVE-2026-44328 is a high-severity vulnerability in Free5gc with a CVSS 3.x base score of 8.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-306.

Key facts

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.

Frequently asked questions

What is CVE-2026-44328?
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.
How severe is CVE-2026-44328?
CVE-2026-44328 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability high.
Is CVE-2026-44328 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (24th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-44328?
CVE-2026-44328 affects Free5gc. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-44328?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-44328 have an EU (EUVD) identifier?
Yes. CVE-2026-44328 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-32570.
When was CVE-2026-44328 published?
CVE-2026-44328 was published on 2026-05-27 and last updated on 2026-06-17.

References

Affected products (1)

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