CVE-2026-55785

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 v3 3.7 LOW

3.7^/10

CVSS v3 : LOW

Vector :

Exploitability : 2.2 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
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

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-28 23:17

Updated : 2026-09-08 21:11

NVD link : CVE-2026-55785

Mitre link : CVE-2026-55785

CVE.ORG link : CVE-2026-55785

JSON object : View

Products Affected

No product.

CWE

CWE-208

Observable Timing Discrepancy

CWE-385

Covert Timing Channel

CWE-532

Insertion of Sensitive Information into Log File

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