CVE-2026-2521
Published: 15 February 2026
Summary
CVE-2026-2521 is a medium-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) 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 47.5th 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-16 (Memory Protection) and SC-7 (Boundary Protection).
Deeper analysis
CVE-2026-2521 is a memory corruption vulnerability (CWE-119) in Open5GS versions up to and including 2.7.6. The issue resides in the sgwc_s5c_handle_create_session_response function within the SGW-C component. 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), indicating medium severity primarily due to its potential for remote denial-of-service impacts.
The vulnerability can be exploited remotely by unauthenticated attackers with low complexity and no user interaction required. Successful exploitation triggers memory corruption, resulting in limited availability disruption, such as crashes or service degradation in the affected SGW-C process. A public exploit is available, enabling potential attacks against exposed Open5GS deployments.
References, including GitHub issues #4282 and related comments in the open5gs/open5gs repository, indicate the project was notified early via an issue report but has not yet responded or issued patches. VulDB entries (ctiid.346109 and id.346109) document the flaw but provide no additional mitigation guidance.
Notable context includes the public availability of an exploit, which could facilitate real-world attacks on unpatched 5G core network implementations using Open5GS. No evidence of active exploitation in the wild is reported.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-6141
Vulnerability details
A weakness has been identified in Open5GS up to 2.7.6. This issue affects the function sgwc_s5c_handle_create_session_response of the component SGW-C. Executing a manipulation can lead to memory corruption. The attack may be performed from remote. The exploit has been made…
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available to the public and could be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Memory corruption vulnerability in exposed network service (SGW-C) directly enables remote exploitation causing process crash/DoS, matching T1499.004 Application or System Exploitation.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly enforces memory protection mechanisms that would block the memory corruption triggered in sgwc_s5c_handle_create_session_response.
Requires validation of inputs to the SGW-C session handling function, addressing the root cause of the CWE-119 flaw before corruption occurs.
Restricts remote network access to the exposed SGW-C component, reducing the attack surface for unauthenticated exploitation of the public vulnerability.