CVE-2026-1975
Published: 06 February 2026
Summary
CVE-2026-1975 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 Exploit Public-Facing Application (T1190); ranked at the 30.3th 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?
Remote unauthenticated null dereference exploit in public-facing 5G network function directly enables T1190 for initial access and T1499.004 for application-layer DoS via crafted input.
NVD Description
A security flaw has been discovered in Free5GC up to 4.1.0. This impacts the function identityTriggerType of the file pfcp_reports.go. The manipulation results in null pointer dereference. The attack can be executed remotely. The exploit has been released to the…
more
public and may be used for attacks. Applying a patch is advised to resolve this issue.
Deeper analysisAI
CVE-2026-1975 is a null pointer dereference vulnerability in the identityTriggerType function within the pfcp_reports.go file of Free5GC, affecting versions up to 4.1.0. Free5GC is an open-source implementation of 5G core network functions. The flaw, associated with CWE-404 ( Improper Resource Shutdown or Release) and CWE-476 (NULL Pointer Dereference), 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), indicating medium severity with low impact primarily on availability.
The vulnerability can be exploited remotely by unauthenticated attackers over the network with low complexity and no user interaction required. Successful exploitation triggers a null pointer dereference, resulting in a denial-of-service condition through application crashes or instability, but without impacts on confidentiality or integrity.
Mitigation involves applying patches, as advised in the vulnerability disclosure. Relevant GitHub references include free5gc/free5gc issues #814 and the associated comment #3831993593, along with a pull request in free5gc/smf #189 that addresses the issue. An exploit is publicly available, increasing the risk of real-world attacks on unpatched systems.
Details
- CWE(s)