Vulnerability 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 Score
LOW
Related Weaknesses (CWE)
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
FAQ
What is CVE-2026-55785?
CVE-2026-55785 is a vulnerability with a CVSS score of 3.7 (LOW). 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 wit...
How severe is CVE-2026-55785?
CVE-2026-55785 has been rated LOW with a CVSS base score of 3.7/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-55785?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.