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 probability: 0.3%, top 79% of all CVEs by exploit prediction. 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(medium)
- EG Risk
- 17(Track)EG Risk 17/100SSVC: 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%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 21%
- KEV
- Not listed
Published
August 28, 2026
Last Modified
September 8, 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.
Affected Packages
(1 across 1 ecosystem)
Go(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| github.com/free5gc/ausf | — | 1.4.5 | — |
Weakness Classification(3)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 8× in last 7d / 29× 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.
- 2026-09-18 19:28 UTCEPSS rescore
- 2026-09-17 19:31 UTCEPSS rescore
- 2026-09-17 03:32 UTCEG score recompute
- 2026-09-16 14:08 UTCEPSS rescore
- 2026-09-16 05:15 UTCEPSS rescore
- 2026-09-15 03:11 UTCEPSS rescore
- 2026-09-14 09:26 UTCEG score recompute
- 2026-09-13 16:47 UTCEPSS rescore
- 2026-09-11 15:20 UTCEG score recompute
- 2026-09-11 14:53 UTCEPSS rescore
- 2026-09-10 09:35 UTCEPSS rescore
- 2026-09-08 22:01 UTCEPSS rescore
- 2026-09-08 21:13 UTCEG score recompute
- 2026-09-07 16:01 UTCEPSS rescore
- 2026-09-06 13:47 UTCEPSS rescore
- 2026-09-06 07:42 UTCEG score recompute
- 2026-09-04 05:07 UTCEPSS rescore
- 2026-09-03 13:36 UTCEG score recompute
- 2026-09-02 14:12 UTCEPSS rescore
- 2026-09-01 13:54 UTCEPSS rescore
- 2026-09-01 04:40 UTCEPSS rescore
- 2026-08-31 19:30 UTCEG score recompute
- 2026-08-31 18:56 UTCEG score recompute
- 2026-08-31 17:34 UTCEG score recompute
- 2026-08-30 19:17 UTCEPSS rescore
Show 4 moreShow fewer
- 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
Related CVEs(same CWE)
Same CWE
10 shownCWE-532
- CVE-2016-0898EG 10.0CRITICAL
- CVE-2018-1264NVD 9.1EG 9.8CRITICAL
- CVE-2018-11717EG 9.8EPSS p95CRITICAL
- CVE-2018-11716EG 9.8EPSS p96CRITICAL
- CVE-2018-0042EG 9.8CRITICAL
- CVE-2018-1072NVD 5.0EG 9.8CRITICAL
- CVE-2018-1117NVD 5.0EG 9.8CRITICAL
- CVE-2018-11320EG 9.8CRITICAL
- CVE-2018-1000123EG 9.8CRITICAL
- CVE-2017-9278NVD 3.3EG 9.8CRITICAL
Frequently asked(5)
What is CVE-2026-55785?
When was CVE-2026-55785 disclosed?
Is CVE-2026-55785 actively exploited?
What is the CVSS score of CVE-2026-55785?
How do I remediate CVE-2026-55785?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-55785
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