Cyber Resilience

CVE-2026-8731

Open5Gs ≤ 2.7.7

Public PoC
Published
17 May 2026
Modified
17 June 2026
Patch / advisory
CVSS Score v4 2.1
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0038 31th percentile
Risk Priority 15 floored blend · peak EPSS

Summary

CVE-2026-8731 is a low-severity Improper Resource Shutdown or Release (CWE-404) vulnerability in Open5Gs Open5Gs. Its CVSS base score is 2.1 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Endpoint Denial of Service (T1499); ranked at the 31th 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 map to AC-10 (Concurrent Session Control) and SC-5 (Denial-of-service Protection) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

A vulnerability has been found in Open5GS up to 2.7.7. Affected is the function ogs_sbi_client_add in the library /lib/sbi/client.c of the component NRF. The manipulation of the argument client_pool leads to denial of service. It is possible to initiate the…

more

attack remotely. The exploit has been disclosed to the public and may be used. 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

T1499 Endpoint Denial of Service Impact
Adversaries may perform Endpoint Denial of Service (DoS) attacks to degrade or block the availability of services to users.
Why these techniques?

Remote DoS via resource handling flaw in network service component directly maps to Endpoint Denial of Service.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

Likely ATT&CK TechniquesAI

Techniques this vulnerability likely enables, inferred from its description, weakness type, and attributed-actor tradecraft. Confidence is per-technique.

T1499 Endpoint Denial of Service Impactconfidence: HIGH
Remote manipulation of client_pool in ogs_sbi_client_add triggers denial of service against the NRF component.
inferred from description + CWE · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-8223Same product: Open5Gs Open5Gs
CVE-2026-8120Same product: Open5Gs Open5Gs
CVE-2026-8222Same product: Open5Gs Open5Gs
CVE-2026-4240Same product: Open5Gs Open5Gs
CVE-2026-1586Same product: Open5Gs Open5Gs
CVE-2026-8290Same product: Open5Gs Open5Gs
CVE-2026-8250Same product: Open5Gs Open5Gs
CVE-2026-8728Same product: Open5Gs Open5Gs
CVE-2025-1925Same product: Open5Gs Open5Gs
CVE-2025-8801Same product: Open5Gs Open5Gs

Affected Assets

open5gs
open5gs
≤ 2.7.7

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SC-5 Denial-of-service Protection
  • AC-10 Concurrent Session Control
Detect
Catch it (NIST detect / respond)
  • SI-4 System Monitoring
Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

prevent

Directly enforces protection mechanisms against resource-exhaustion DoS triggered by manipulation of client_pool in ogs_sbi_client_add.

prevent

Limits concurrent client sessions/connections, preventing the pool exhaustion that the CVE exploits remotely.

detect

Enables monitoring of SBI/NRF resource usage and anomalous client additions that indicate the ongoing DoS condition.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly include coding standards for correct resource allocation and release.

DE.CM-09 partial match
prevents

Runtime monitoring can detect resource exhaustion caused by improper shutdown or release.

ID.AM-08 partial match
prevents

Lifecycle management of assets can encompass proper resource release at end-of-life or shutdown.

PR.IR-04 partial match
prevents

Capacity management helps surface leaks from unreleased resources but does not prevent the coding flaw.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Including restart, recovery and media-handling instructions reduces the likelihood that resources or sensitive data will be left in an exposed or improperly released state after a failure.

References