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TI-2026-25505 Aliases CVE-2026-33063GHSA-4jrw-92fg-4jwx

free5GC AUSF UE Authentication Panic on Nil SuciSupiMap Interface Conversion

Priority MEDIUM 45CWE-476Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-476.

Summary

free5GC is an open source 5G core network. free5GC AUSF prior to version 1.4.2 has is an Improper Null Check vulnerability leading to Denial of Service. All deployments of free5GC v4.0.1 using the AUSF UE authentication service (`/nausf-auth/v1/ue-authentications` endpoint) are affected. A remote attacker can cause the AUSF service to panic and crash by sending a crafted UE authentication request that triggers a nil interface conversion in the `GetSupiFromSuciSupiMap` function. This results in complete denial of service for the AUSF authentication service. The `GetSupiFromSuciSupiMap` function attempts to perform an interface conversion from `interface{}` to `*context.SuciSupiMap` without checking if the underlying value is nil. When `SuciSupiMap` is nil, the code panics with "interface conversion: interface {} is nil, not *context.SuciSupiMap". free5GC AUSF version 1.4.2 patches the issue. There is no direct workaround at the application level. The recommendation is to apply the provided patch or restrict access to the AUSF API to trusted sources only.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00692 53rd percentileScored 2026-11-07
Fix Fixed ausf (free5gc): 1.4.2github.com/free5gc/ausf (Go): 1.4.2

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
free5gcausfbefore 1.4.21.4.2Patch availableCNA
—github.com/free5gc/ausf (Go)before 1.4.21.4.2Patch availableGHSA-4jrw-92fg-4jwx
  • ausf Vendorfree5gc Affected before 1.4.2 Fixed in 1.4.2 Patch available CNA
  • github.com/free5gc/ausf (Go) Vendor— Affected before 1.4.2 Fixed in 1.4.2 Patch available GHSA-4jrw-92fg-4jwx

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:free5gc:free5gc:*:*:*:*:*:*:*:*before 1.4.2Vulnerablefree5gc
  • cpe:2.3:a:free5gc:free5gc:*:*:*:*:*:*:*:* Versions before 1.4.2 Vulnerable ·free5gc

Remediation

  • Fix · CNA ausf (free5gc) Fixed in 1.4.2
  • Fix · GHSA-4jrw-92fg-4jwx github.com/free5gc/ausf (Go) Fixed in 1.4.2 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-33063
  2. 2026-10-03 Alias added: GHSA-4jrw-92fg-4jwx

References

Patch 2

Advisory 2

Other 2

  • TI-2026-32298 Incorrect authorization in free5gc CVSS 3.1CRITICAL 10.0
  • TI-2026-32297 free5GC: SMF UPI management interface lacks auth middleware; unauthenticated topology read/write requests reach handlers CVSS 3.1CRITICAL 10.0
  • TI-2026-32295 free5GC: NEF nnef-oam route group is unauthenticated; no-token requests reach the OAM handler CVSS 3.1CRITICAL 10.0
  • TI-2025-39412 free5gc v4.1.0 and before is vulnerable to Buffer Overflow. CVSS 3.1CRITICAL 9.8
  • TI-2026-32294 Missing authorization in free5gc CVSS 3.1CRITICAL 9.4
  • TI-2026-32283 Missing authorization in free5gc CVSS 3.1CRITICAL 9.4
See all 58 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences