{"id":"CVE-2026-5818","summary":"MCU Firmware Update Authentication Bypass on Caliptra Core","details":"Incorrect check of function return value in Caliptra Core Runtime Firmware (ActivateFirmwareCmd::activate_fw modules) allows bypass of Caliptra Core's verification of the MCU FW during a hitless update.\n\nThis issue affects Core Runtime Firmware: from 2.0.0 through 2.0.1, 2.1.0.","aliases":["GHSA-456r-gcjr-6rxq"],"modified":"2026-07-15T01:49:17.272164539Z","published":"2026-06-23T23:50:06.556Z","database_specific":{"cna_assigner":"Caliptra","cwe_ids":["CWE-253"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/5xxx/CVE-2026-5818.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/5xxx/CVE-2026-5818.json"},{"type":"ADVISORY","url":"https://github.com/chipsalliance/caliptra-sw/security/advisories/GHSA-456r-gcjr-6rxq"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-5818"},{"type":"PACKAGE","url":"https://github.com/chipsalliance/caliptra-sw"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/chipsalliance/caliptra-sw","events":[{"introduced":"62c8009df12bb5e6d63479e82b8335aaa8ba84c6"},{"fixed":"3824083e4632ecbdff50aa2e723e89fa42d9dcf6"}],"database_specific":{"source":"DESCRIPTION","extracted_events":[{"introduced":"2.0.0"},{"fixed":"2.0.1"}]}}],"versions":["2.1.0","release_v20260207_0-2.0","release_v20260120_0-2.0","release_v20251204_0-2.x","release_v20251203_0-2.x","release_v20251128_0-2.x","release_v20251126_0-2.x","release_v20251125_1-2.x","fw-2.0.0","release_v20251125_0-2.x","release_v20251122_0-2.x","rom-2.0.0","release_v20251121_0-2.x","release_v20251120_1-2.x"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-5818.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:A/AC:L/AT:P/PR:H/UI:N/VC:N/VI:H/VA:H/SC:H/SI:H/SA:H"}]}