Is there a public PoC exploit available for CVE-2026-8120?

Yes, a public proof-of-concept exploit is available for CVE-2026-8120. Prioritise patching immediately. EPSS: 0.0%.

Open5GS CVE-2026-8120

Q: What is the CVSS score of CVE-2026-8120?

CVE-2026-8120 has a CVSS 4.0 base score of 2.1 (Low). CVSS vector: CVSS: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 exploitation probability: 0.0%.

EUVD-2026-28478 LOW

Improper Resource Shutdown or Release (CWE-404)

2026-05-08 VulDB

GHSA-x7c4-pm53-48h6

Denial Of Service Open5gs

2.1

CVSS 4.0 · NVD

Severity by source

NVD PRIMARY

2.1 LOW

CVSS: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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS: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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Lifecycle Timeline

Analysis Generated

May 08, 2026 - 01:30 vuln.today

Severity Changed

May 08, 2026 - 01:22 NVD

MEDIUM LOW

CVSS changed

May 08, 2026 - 01:22 NVD

4.3 (MEDIUM) 2.1 (LOW)

CVE Published

May 08, 2026 - 00:15 nvd

LOW 2.1

DescriptionCVE.org

A flaw has been found in Open5GS up to 2.7.7. The affected element is the function nssf_nnrf_nsselection_handle_get_from_amf_or_vnssf of the file /src/nssf/nnssf-handler.c of the component NSSF. Executing a manipulation can lead to denial of service. The attack can be executed remotely. The exploit has been published and may be used. The project was informed of the problem early through an issue report but has not responded yet.

AnalysisAI

Denial of service in Open5GS up to version 2.7.7 allows authenticated remote attackers to manipulate the NSSF network selection function via the nssf_nnrf_nsselection_handle_get_from_amf_or_vnssf handler in /src/nssf/nnssf-handler.c, causing service unavailability. Public exploit code exists and the vulnerability has been reported to the project, though no patch has been released as of analysis time.

Technical ContextAI

Open5GS is an open-source 5G core network implementation. The vulnerability resides in the NSSF (Network Slice Selection Function) component, specifically within the handler responsible for processing network slice selection requests from the AMF (Access and Mobility Management Function) or vNSSF (virtual NSSF). The affected function fails to properly validate or sanitize manipulation of input related to network slice selection, leading to improper resource handling classified under CWE-404 (Improper Resource Validation). The NSSF is a critical signaling component in 5G networks tasked with selecting appropriate network slices for incoming service requests. The vulnerability allows authenticated entities within the 5G control plane to trigger denial of service conditions.

RemediationAI

Upgrade Open5GS to a version beyond 2.7.7 once the project releases a patched version. As of analysis time, no vendor-released patch has been identified; monitor the official Open5GS GitHub repository and release notes for updates addressing this NSSF handler vulnerability. In the interim, implement network segmentation to restrict access to the NSSF component to only trusted AMF and vNSSF entities by deploying firewall rules limiting TCP/UDP traffic to NSSF ports (typically 8080, 7777 depending on configuration) to authorized signaling network addresses only. Enable authentication verification on all NSSF-facing interfaces and enforce mutual TLS (mTLS) for control plane communication if not already deployed. Monitor NSSF logs for repeated failed network slice selection requests from the same source, which may indicate exploitation attempts. These mitigations reduce exposure but do not eliminate the vulnerability; patching remains the primary remediation path.