CVE-2025-15539
Published: 19 January 2026
Summary
CVE-2025-15539 is a medium-severity Improper Resource Shutdown or Release (CWE-404) vulnerability in Open5Gs Open5Gs. 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 16.9th 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 exploitation of the flaw in sgwc directly causes application crash/DoS, matching T1499.004 Application or System Exploitation.
NVD Description
A vulnerability was determined in Open5GS up to 2.7.6. Impacted is the function sgwc_s11_handle_downlink_data_notification_ack of the file src/sgwc/s11-handler.c of the component sgwc. This manipulation causes denial of service. The attack can be initiated remotely. The exploit has been publicly disclosed…
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and may be utilized. Patch name: b4707272c1caf6a7d4dca905694ea55557a0545f. To fix this issue, it is recommended to deploy a patch. The issue report is flagged as already-fixed.
Deeper analysisAI
CVE-2025-15539 is a denial-of-service vulnerability affecting Open5GS versions up to 2.7.6. The issue resides in the sgwc_s11_handle_downlink_data_notification_ack function within the file src/sgwc/s11-handler.c of the sgwc component. It stems from CWE-404 and 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 availability impact but no confidentiality or integrity effects.
A remote attacker can exploit this vulnerability without privileges, user interaction, or high complexity over the network. Successful exploitation triggers a denial of service, disrupting the sgwc component's functionality. The exploit has been publicly disclosed and may be utilized by attackers.
Mitigation is available via the patch at commit b4707272c1caf6a7d4dca905694ea55557a0545f in the Open5GS GitHub repository. Security practitioners should deploy this patch promptly, as the issue is reported as already fixed. Additional details are documented in GitHub issues #4230 and related comments, along with the VulDB entry.
Details
- CWE(s)