CVE-2026-33063

HIGH EPSS 46.6%
Published Mar 20, 20263mo ago · Modified Jun 17, 20262w ago
8.7 CVSS 4.0
High
Find Similar
Published Mar 20, 2026 3mo ago
Last Modified Jun 17, 2026 2w ago

Description

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.

CVSS Details

Base Score
8.7
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
46.6% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-476 NULL Pointer Dereference Memory Safety

Affected Products 1

VendorProductVersionRange
free5gcfree5gc* <1.4.2

References 4

  • github.com https://github.com/free5gc/ausf/commit/3b9ac4403c2756dc89a5ed3cdcefe688458588aa
    Patch
  • github.com https://github.com/free5gc/ausf/pull/52
    Issue TrackingPatch
  • github.com https://github.com/free5gc/free5gc/issues/778
    Issue Tracking
  • github.com https://github.com/free5gc/free5gc/security/advisories/GHSA-4jrw-92fg-4jwx
    Vendor Advisory

Remediation

  • github.com https://github.com/free5gc/ausf/commit/3b9ac4403c2756dc89a5ed3cdcefe688458588aa
    Patch
  • github.com https://github.com/free5gc/ausf/pull/52
    Issue TrackingPatch