CVE-2026-1684
Published: 30 January 2026
Summary
CVE-2026-1684 is a medium-severity Improper Resource Shutdown or Release (CWE-404) vulnerability in Free5Gc Free5Gc. Its CVSS base score is 5.3 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 35.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
Threat & Defense at a Glance
Threat & Defense Details
Likely Mitigating ControlsAI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Contingency plan updates incorporate proper resource shutdown and release steps, preventing attackers from leveraging incomplete cleanup during recovery scenarios.
Mandates explicit shutdown of the network connection at session conclusion, directly addressing improper resource release.
Requires proper shutdown/release procedures that include overwriting or isolating data to block unintended transfer via reused system objects.
Procedures can mandate orderly shutdown or release of resources when failures occur, preventing improper resource handling after a fault.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The CVE describes remote exploitation of a software flaw in a network-exposed PFCP UDP endpoint (HandleReports) that directly results in application/service unavailability, matching T1499.004 Application or System Exploitation for Endpoint DoS.
NVD Description
A vulnerability was found in Free5GC SMF up to 4.1.0. Affected by this issue is the function HandleReports of the file /internal/context/pfcp_reports.go of the component PFCP UDP Endpoint. The manipulation results in denial of service. The attack can be executed…
more
remotely. It is advisable to implement a patch to correct this issue.
Deeper analysisAI
CVE-2026-1684 is a denial-of-service vulnerability in Free5GC SMF versions up to 4.1.0. The issue affects the HandleReports function in the file /internal/context/pfcp_reports.go within the PFCP UDP Endpoint component. Published on 2026-01-30, it has a CVSS v3.1 base score of 5.3 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L) and is associated with CWE-404.
The vulnerability can be exploited remotely by unauthenticated attackers with network access and low complexity requirements, requiring no user interaction. Successful exploitation leads to a denial of service, impacting availability with low severity due to unchanged scope and no effects on confidentiality or integrity.
Mitigation involves applying an available patch, as recommended in the vulnerability description. Relevant resources include the GitHub issue at https://github.com/free5gc/free5gc/issues/806, the SMF repository at https://github.com/free5gc/smf/, and the pull request at https://github.com/free5gc/smf/pull/188, along with details from VulDB at https://vuldb.com/?ctiid.343477 and https://vuldb.com/?id.343477.
Details
- CWE(s)