# CVE-2026-55785

## Summary

- **CVE ID:** CVE-2026-55785
- **Severity:** LOW
- **CVSS Score:** 3.7 (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
- **Published:** Aug 28, 2026
- **Last Modified:** Aug 31, 2026

## 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.

## Affected Products

- free5gc — free5gc (< 1.4.5)

## References

- [CNA](https://github.com/free5gc/free5gc/security/advisories/GHSA-fp46-6vfw-gc9c)
- [CNA](https://github.com/free5gc/ausf/pull/63)
- [CNA](https://github.com/free5gc/ausf/commit/7a5a4aa1ec6cd0e1febebf333911c3104968edf0)
- [CNA](https://github.com/free5gc/ausf/releases/tag/v1.4.5)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.28%
- **EPSS Percentile:** 20.6

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-09._