CVE-2026-4240

Open5GS CCA smf_s6b_sta_cb denial of service

State: Published
Severity: 6.9 Medium
Published: Mar 16, 2026
Updated: Mar 16, 2026
Reserved: Mar 15, 2026

Description

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.

Scores

CVSS	Score	Vector	Source
4.0	6.9 Medium	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P	VulDB
3.1	5.3 Medium	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C	VulDB
3.0	5.3 Medium	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C	VulDB
2.0	5.0 Medium	AV:N/AC:L/Au:N/C:N/I:N/A:P/E:POC/RL:OF/RC:C	VulDB

Weaknesses

CWE-404 Denial of Service

Affected Products

Product	Versions
Open5GSn/a	2.7.0Affected 2.7.1Affected 2.7.2Affected 2.7.3Affected 2.7.4Affected 2.7.5Affected 2.7.6Affected 2.7.7Not affected

References

VDB-351182 | Open5GS CCA smf_s6b_sta_cb denial of servicevdb-entrytechnical-description
VDB-351182 | CTI Indicators (IOB, IOC, TTP, IOA)signaturepermissions-required
Submit #771361 | Open5GS MME v2.7.6 Improper Authenticationthird-party-advisory
https://github.com/open5gs/open5gs/issues/4343issue-tracking
https://github.com/open5gs/open5gs/issues/4343#issue-4021871895exploitissue-tracking
https://github.com/open5gs/open5gs/commit/80eb484a6ab32968e755e628b70d1a9c64f012ecpatch
https://github.com/open5gs/open5gs/releases/tag/v2.7.7patch
https://github.com/open5gs/open5gs/product

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