{"id":"CVE-2026-55785","summary":"free5GC AUSF uses non-constant-time authentication comparisons and logs XRES* in 5G-AKA","details":"free5GC is an open-source implementation of the 5G core network. Prior to 1.4.5, the AUSF component performs cryptographic authentication comparisons in internal/sbi/processor/ue_authentication.go with ordinary equality helpers. Auth5gAkaComfirmRequestProcedure compares RES* and XRES* with strings.EqualFold and logs the expected XRES* value at INFO level before comparison. EapAuthComfirmRequestProcedure compares AT_MAC and XMAC with bytes.Equal and evaluates XRES == RES with ordinary string equality. These comparisons can return at mismatch-dependent times, although testing did not demonstrate a practical remote timing oracle because of HTTP/SBI timing noise. The INFO log exposes authentication material to operators, log collectors, sidecars, or processes able to read AUSF logs. This issue is fixed in version 1.4.5.","aliases":["GHSA-fp46-6vfw-gc9c"],"modified":"2026-09-01T03:30:34.142678245Z","published":"2026-08-28T22:25:06.814Z","database_specific":{"cwe_ids":["CWE-208","CWE-385","CWE-532"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55785.json","cna_assigner":"GitHub_M"},"references":[{"type":"WEB","url":"https://github.com/free5gc/ausf/releases/tag/v1.4.5"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55785.json"},{"type":"ADVISORY","url":"https://github.com/free5gc/free5gc/security/advisories/GHSA-fp46-6vfw-gc9c"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55785"},{"type":"FIX","url":"https://github.com/free5gc/ausf/commit/7a5a4aa1ec6cd0e1febebf333911c3104968edf0"},{"type":"FIX","url":"https://github.com/free5gc/ausf/pull/63"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/free5gc/ausf","events":[{"introduced":"0"},{"fixed":"7a5a4aa1ec6cd0e1febebf333911c3104968edf0"},{"fixed":"b74ee7dafec5975e3440ae95125994565cfb0496"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"1.4.5"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["v1.4.4","v1.4.3","v1.4.2","v1.4.1","v1.4.0","v1.3.2","v1.3.1","v1.3.0","v1.2.4","v1.2.3","v1.2.2","v1.2.1","v1.2.0","v1.1.1","v1.1.0","v1.0.2","v1.0.1","v1.0.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55785.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N"}]}