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.
CVE-2026-55785
This low-severity CVE scores 3.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- Lower severity and no public exploit yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 3.7
- EG Score
- 3.7(low)
- EG Risk
- 21(Track)EG Risk 21/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity37% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 20%
- KEV
- Not listed
Published
August 28, 2026
Last Modified
August 28, 2026
References (4)
- security-advisories@githubhttps://github.com/free5gc/ausf/commit/7a5a4aa1ec6cd0e1febebf333911c3104968edf0
- security-advisories@githubhttps://github.com/free5gc/ausf/pull/63
- security-advisories@githubhttps://github.com/free5gc/ausf/releases/tag/v1.4.5
- security-advisories@githubhttps://github.com/free5gc/free5gc/security/advisories/GHSA-fp46-6vfw-gc9c
Vendor Advisories for CVE-2026-55785(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(3)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 4× in last 7d / 4× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-08-30 01:22 UTCEPSS rescore
- 2026-08-28 23:25 UTCEG score recompute
- 2026-08-28 22:35 UTCEG score recompute
- 2026-08-28 22:33 UTCMITRE cvelistV5first tracked
Frequently asked(5)
What is CVE-2026-55785?
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Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-55785
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