TI-2026-03687 Aliases CVE-2026-4240 GHSA-wq9j-47c8-8fpr

Open5GS CCA smf_s6b_sta_cb denial of service

HIGH 70CWE-404Published 2026-03-16 · Updated 2026-03-16

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Attack requirements: None
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · Low
Fix status: Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-404.

Summary

A vulnerability was determined in Open5GS up to 2.7.6. The affected element is the function smf_gx_cca_cb/smf_gy_cca_cb/smf_s6b_aaa_cb/smf_s6b_sta_cb of the component CCA Handler. This manipulation causes denial of service. The attack can be initiated remotely. The exploit has been publicly disclosed and may be utilized. Upgrading to version 2.7.7 is sufficient to fix this issue. Patch name: 80eb484a6ab32968e755e628b70d1a9c64f012ec. Upgrading the affected component is recommended.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV

EPSS 0.00567 47th percentileScored 2026-11-07

Public exploit Yes 1 exploit referenceTagged by the CNA and NVD

Fix Fixed Open5GS: 2.7.7

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: Poc
Automatable: Yes
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
—	Open5GS	2.7.0; 2.7.1; 2.7.2; 2.7.3; 2.7.4; 2.7.5; 2.7.6	2.7.7	Patch available	CNA

Open5GS Vendor— Affected 2.7.0; 2.7.1; 2.7.2; 2.7.3; 2.7.4; 2.7.5; 2.7.6 Fixed in 2.7.7 Patch available CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:open5gs:open5gs::::::::	before 2.7.7	Vulnerable	Open5GS

cpe:2.3:a:open5gs:open5gs:*:*:*:*:*:*:*:* Versions before 2.7.7 Vulnerable ·Open5GS

Remediation

Fix · CNA Open5GS Fixed in 2.7.7

Timeline

2026-10-02 Threatist record created from CVE-2026-4240
2026-10-03 Alias added: GHSA-wq9j-47c8-8fpr
2026-10-25 EPSS moved to the below the 50th percentile

References

Exploit 1

https://github.com/open5gs/open5gs/issues/4343#issue-4021871895

Patch 2

Advisory 1

https://github.com/open5gs/open5gs/issues/4343

Other 1

https://github.com/open5gs/open5gs/

TI-2024-26883 open5gs v2.6.4 is vulnerable to Buffer Overflow. CVSS 3.1CRITICAL 9.8
TI-2024-26882 Open5GS v2.6.4 is vulnerable to Buffer Overflow. CVSS 3.1CRITICAL 9.8
TI-2024-22649 Open5GS MME versions <= 2.6.4 contains an assertion that can be remotely triggered via a… CVSS 3.1HIGH 8.6
TI-2023-18757 Open5GS MME versions <= 2.6.4 contain a reachable assertion in the `Uplink NAS Transport`… CVSS 3.1HIGH 8.6
TI-2023-18755 Open5GS MME version <= 2.6.4 contains an assertion that can be remotely triggered via a… CVSS 3.1HIGH 8.6
TI-2023-18754 Open5GS MME versions <= 2.6.4 contain an assertion that can be remotely triggered via a… CVSS 3.1HIGH 8.6

See all 153 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences