CVE-2026-1587
Published: 29 January 2026
Summary
CVE-2026-1587 is a medium-severity Improper Resource Shutdown or Release (CWE-404) vulnerability in Open5Gs Open5Gs. Its CVSS base score is 5.5 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 48.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 SI-2 (Flaw Remediation) and SC-5 (Denial-of-service Protection).
Deeper analysis
CVE-2026-1587 is a denial-of-service vulnerability affecting Open5GS versions up to 2.7.6. The issue resides in the sgwc_s11_handle_modify_bearer_request function within the file /sgwc/s11-handler.c of the SGWC component. Manipulation of this function triggers a denial of service, classified under CWE-404, with 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).
The vulnerability can be exploited remotely by unauthenticated attackers with network access, requiring low complexity and no user interaction. Successful exploitation results in limited disruption to availability, such as partial denial of service on the affected SGWC instance, without impacting confidentiality or integrity.
Advisories recommend applying a patch to mitigate the issue, which has been flagged as already fixed. Relevant details are documented in Open5GS GitHub repository issue #4272, including exploit disclosure, and further tracked on VulDB (ctiid.343350). The exploit has been publicly disclosed and may be usable.
Notable context includes the public availability of the exploit, increasing the risk for unpatched Open5GS deployments in 5G core network environments. No real-world exploitation in the wild has been reported.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-4998
Vulnerability details
A vulnerability has been found in Open5GS up to 2.7.6. The affected element is the function sgwc_s11_handle_modify_bearer_request of the file /sgwc/s11-handler.c of the component SGWC. The manipulation leads to denial of service. It is possible to initiate the attack remotely.…
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The exploit has been disclosed to the public and may be used. Applying a patch is the recommended action to fix this issue. The issue report is flagged as already-fixed.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Direct application-layer DoS via remote exploitation of a specific function (CWE-404) matches T1499.004 Application or System Exploitation.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly requires timely application of the vendor patch that resolves the sgwc_s11_handle_modify_bearer_request flaw.
Mandates technical controls that limit the impact of remote unauthenticated manipulation leading to partial DoS on the SGWC.
Requires validation of incoming modify-bearer signaling to reject malformed input that triggers the CWE-404 resource-handling failure.