CVE-2026-1522
Published: 28 January 2026
Summary
CVE-2026-1522 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 24.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 SC-5 (Denial-of-service Protection) and SI-2 (Flaw Remediation).
Deeper analysis
CVE-2026-1522 is a vulnerability in Open5GS versions up to and including 2.7.6, affecting the SGWC component. Specifically, it resides in the sgwc_s5c_handle_modify_bearer_response function within the file src/sgwc/s5c-handler.c. The issue, classified under CWE-404, enables a denial of service through improper resource handling, 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 triggers a denial of service condition, disrupting service availability without impacting confidentiality or integrity.
Mitigation is available via the patch commit b19cf6a in the Open5GS GitHub repository, which resolves the issue as confirmed in issue tracker #4266. Security practitioners are advised to apply this patch promptly, as the vulnerability is already fixed upstream and an exploit has been publicly disclosed.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-4881
Vulnerability details
A weakness has been identified in Open5GS up to 2.7.6. This vulnerability affects the function sgwc_s5c_handle_modify_bearer_response of the file src/sgwc/s5c-handler.c of the component SGWC. Executing a manipulation can lead to denial of service. The attack can be launched remotely. The…
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exploit has been made available to the public and could be used for attacks. This patch is called b19cf6a. Applying a patch is advised to resolve this issue. The issue report is flagged as already-fixed.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Remote unauthenticated exploitation of improper resource handling (CWE-404) in SGWC directly enables application/system DoS via crafted network traffic.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly requires applying the available patch (b19cf6a) that fixes the improper resource release flaw in sgwc_s5c_handle_modify_bearer_response.
Explicitly protects against remote denial-of-service attacks that exploit resource-handling weaknesses to degrade SGWC availability.
Limits the effects of resource exhaustion triggered by crafted modify-bearer responses before service disruption occurs.