{"id":"CVE-2026-4240","state":"PUBLISHED","title":"Open5GS CCA smf_s6b_sta_cb denial of service","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.","publishedAt":"2026-03-16T13:32:09.729Z","updatedAt":"2026-03-16T14:25:31.568Z","severity":{"score":6.9,"label":"Medium","version":"4.0","vector":"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","source":"VulDB"},"assigner":"VulDB","products":["n/a Open5GS"],"affected":[{"vendor":"n/a","product":"Open5GS","versions":[{"version":"2.7.0","status":"affected"},{"version":"2.7.1","status":"affected"},{"version":"2.7.2","status":"affected"},{"version":"2.7.3","status":"affected"},{"version":"2.7.4","status":"affected"},{"version":"2.7.5","status":"affected"},{"version":"2.7.6","status":"affected"},{"version":"2.7.7","status":"unaffected"}],"cpes":["cpe:2.3:a:open5gs:open5gs:*:*:*:*:*:*:*:*"],"modules":["CCA Handler"]}],"references":["https://vuldb.com/?id.351182","https://vuldb.com/?ctiid.351182","https://vuldb.com/?submit.771361","https://github.com/open5gs/open5gs/issues/4343","https://github.com/open5gs/open5gs/issues/4343#issue-4021871895","https://github.com/open5gs/open5gs/commit/80eb484a6ab32968e755e628b70d1a9c64f012ec","https://github.com/open5gs/open5gs/releases/tag/v2.7.7","https://github.com/open5gs/open5gs/"],"weaknesses":["CWE-404"],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/4xxx/CVE-2026-4240.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-4240","state":"PUBLISHED","datePublished":"2026-03-16T13:32:09.729Z","dateUpdated":"2026-03-16T14:25:31.568Z","assignerShortName":"VulDB","assignerOrgId":"1af790b2-7ee1-4545-860a-a788eba489b5","dateReserved":"2026-03-15T20:40:37.925Z"},"containers":{"cna":{"title":"Open5GS CCA smf_s6b_sta_cb denial of service","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"n/a","product":"Open5GS","versions":[{"version":"2.7.0","status":"affected"},{"version":"2.7.1","status":"affected"},{"version":"2.7.2","status":"affected"},{"version":"2.7.3","status":"affected"},{"version":"2.7.4","status":"affected"},{"version":"2.7.5","status":"affected"},{"version":"2.7.6","status":"affected"},{"version":"2.7.7","status":"unaffected"}],"cpes":["cpe:2.3:a:open5gs:open5gs:*:*:*:*:*:*:*:*"],"modules":["CCA Handler"]}],"references":[{"url":"https://vuldb.com/?id.351182","name":"VDB-351182 | Open5GS CCA smf_s6b_sta_cb denial of service","tags":["vdb-entry","technical-description"]},{"url":"https://vuldb.com/?ctiid.351182","name":"VDB-351182 | CTI Indicators (IOB, IOC, TTP, IOA)","tags":["signature","permissions-required"]},{"url":"https://vuldb.com/?submit.771361","name":"Submit #771361 | Open5GS MME v2.7.6 Improper Authentication","tags":["third-party-advisory"]},{"url":"https://github.com/open5gs/open5gs/issues/4343","tags":["issue-tracking"]},{"url":"https://github.com/open5gs/open5gs/issues/4343#issue-4021871895","tags":["exploit","issue-tracking"]},{"url":"https://github.com/open5gs/open5gs/commit/80eb484a6ab32968e755e628b70d1a9c64f012ec","tags":["patch"]},{"url":"https://github.com/open5gs/open5gs/releases/tag/v2.7.7","tags":["patch"]},{"url":"https://github.com/open5gs/open5gs/","tags":["product"]}],"metrics":[{"cvssV4_0":{"version":"4.0","baseScore":6.9,"vectorString":"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","baseSeverity":"MEDIUM"}},{"cvssV3_1":{"version":"3.1","baseScore":5.3,"vectorString":"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","baseSeverity":"MEDIUM"}},{"cvssV3_0":{"version":"3.0","baseScore":5.3,"vectorString":"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","baseSeverity":"MEDIUM"}},{"cvssV2_0":{"version":"2.0","baseScore":5,"vectorString":"AV:N/AC:L/Au:N/C:N/I:N/A:P/E:POC/RL:OF/RC:C"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-404","type":"CWE","lang":"en","description":"Denial of Service"}]}],"providerMetadata":{"shortName":"VulDB","orgId":"1af790b2-7ee1-4545-860a-a788eba489b5","dateUpdated":"2026-03-16T13:32:09.729Z"},"timeline":[{"time":"2026-03-15T00:00:00.000Z","lang":"en","value":"Advisory disclosed"},{"time":"2026-03-15T01:00:00.000Z","lang":"en","value":"VulDB entry created"},{"time":"2026-03-15T21:45:43.000Z","lang":"en","value":"VulDB entry last update"}],"credits":[{"lang":"en","value":"ZiyuLin (VulDB User)","type":"reporter"}],"tags":["x_open-source"]},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-16T14:25:25.980922Z","id":"CVE-2026-4240","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-03-16T14:25:31.568Z"}}]}}}