{"id":"CVE-2026-55785","title":"free5GC is an open-source implementation of the 5G core network","summary":"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. Auth5gAk…","severity":"low","cvss":3.7,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N","cwe":["CWE-208","CWE-385","CWE-532"],"vendor":"free5gc","product":"github.com/free5gc/ausf","affected":["github.com/free5gc/ausf < 1.4.5"],"patched":["github.com/free5gc/ausf 1.4.5"],"published":"2026-08-28","updated":"2026-09-08","sourceUpdated":"2026-09-08T21:11:31.703","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-55785","references":[{"url":"https://github.com/free5gc/ausf/commit/7a5a4aa1ec6cd0e1febebf333911c3104968edf0","label":"security-advisories@github.com"},{"url":"https://github.com/free5gc/ausf/pull/63","label":"security-advisories@github.com"},{"url":"https://github.com/free5gc/ausf/releases/tag/v1.4.5","label":"security-advisories@github.com"},{"url":"https://github.com/free5gc/free5gc/security/advisories/GHSA-fp46-6vfw-gc9c","label":"security-advisories@github.com"},{"url":"https://github.com/advisories/GHSA-fp46-6vfw-gc9c"}],"tags":["nvd","ghsa","go"],"epss":0.00284,"epssPercentile":0.2115,"aliases":["GHSA-fp46-6vfw-gc9c"],"ecosystem":"go","ingestedAt":"2026-08-28T23:26:57.556Z","slug":"CVE-2026-55785","body":"## Overview\n\nfree5GC 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-55785)\n\nAffected packages:\n\n- `github.com/free5gc/ausf < 1.4.5`\n\nPatched in:\n\n- `github.com/free5gc/ausf 1.4.5`\n\nSource: https://github.com/advisories/GHSA-fp46-6vfw-gc9c","depth":"sunlit","depthScore":20,"depthScoreParts":{"impact":20.4,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}