{"cve":"CVE-2026-55785","nvd":{"published":"2026-08-28T23:17:07.697","modified":"2026-09-08T21:11:31.703","status":"Deferred","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N","score":3.7},"cwes":["CWE-208","CWE-385","CWE-532"],"references":["https://github.com/free5gc/ausf/commit/7a5a4aa1ec6cd0e1febebf333911c3104968edf0","https://github.com/free5gc/ausf/pull/63","https://github.com/free5gc/ausf/releases/tag/v1.4.5","https://github.com/free5gc/free5gc/security/advisories/GHSA-fp46-6vfw-gc9c"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:50:50.842544443+00:00"},"epss":{"cve":"CVE-2026-55785","score":0.00445,"percentile":0.38719,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-fp46-6vfw-gc9c","url":"https://osv.dev/vulnerability/GHSA-fp46-6vfw-gc9c","summary":"free5GC AUSF uses non-constant-time authentication comparisons and logs XRES* in 5G-AKA","modified":"2026-09-02T19:55:42.818084205Z","packages":[{"ecosystem":"Go","name":"github.com/free5gc/ausf","purl":"pkg:golang/github.com/free5gc/ausf","ranges":["<1.4.5"],"fixed":["1.4.5"]}]},{"id":"GO-2026-6328","url":"https://osv.dev/vulnerability/GO-2026-6328","summary":"free5GC AUSF uses non-constant-time authentication comparisons and logs XRES* in 5G-AKA in github.com/free5gc/ausf","modified":"2026-09-02T19:45:14.135011150Z","packages":[{"ecosystem":"Go","name":"github.com/free5gc/ausf","purl":"pkg:golang/github.com/free5gc/ausf","ranges":["<1.4.5"],"fixed":["1.4.5"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}