CVE-2026-33063

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 v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

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

Configurations

Configuration 1 (hide)

cpe:2.3:a:free5gc:free5gc:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-03-20 03:16

Updated : 2026-03-27 17:06

NVD link : CVE-2026-33063

Mitre link : CVE-2026-33063

CVE.ORG link : CVE-2026-33063

JSON object : View

Products Affected

free5gc

free5gc

CWE

CWE-476

NULL Pointer Dereference

{"id": "CVE-2026-33063", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 3.9}], "cvssMetricV40": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 8.7, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "HIGH", "valueDensity": "NOT_DEFINED", "vectorString": "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", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "NONE", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "published": "2026-03-20T03:16:01.260", "references": [{"url": "https://github.com/free5gc/ausf/commit/3b9ac4403c2756dc89a5ed3cdcefe688458588aa", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/free5gc/ausf/pull/52", "tags": ["Issue Tracking", "Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/free5gc/free5gc/issues/778", "tags": ["Issue Tracking"], "source": "security-advisories@github.com"}, {"url": "https://github.com/free5gc/free5gc/security/advisories/GHSA-4jrw-92fg-4jwx", "tags": ["Vendor Advisory"], "source": "security-advisories@github.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-476"}]}], "descriptions": [{"lang": "en", "value": "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."}, {"lang": "es", "value": "free5GC es una red central 5G de c\u00f3digo abierto. free5GC AUSF anterior a la versi\u00f3n 1.4.2 tiene una vulnerabilidad de verificaci\u00f3n de nulos incorrecta que conduce a la denegaci\u00f3n de servicio. Todas las implementaciones de free5GC v4.0.1 que utilizan el servicio de autenticaci\u00f3n de UE de AUSF (el endpoint '/nausf-auth/v1/ue-authentications') est\u00e1n afectadas. Un atacante remoto puede causar que el servicio AUSF entre en p\u00e1nico y falle al enviar una solicitud de autenticaci\u00f3n de UE manipulada que activa una conversi\u00f3n de interfaz nula en la funci\u00f3n 'GetSupiFromSuciSupiMap'. Esto resulta en una denegaci\u00f3n de servicio completa para el servicio de autenticaci\u00f3n de AUSF. La funci\u00f3n 'GetSupiFromSuciSupiMap' intenta realizar una conversi\u00f3n de interfaz de 'interface{}' a '*context.SuciSupiMap' sin verificar si el valor subyacente es nulo. Cuando 'SuciSupiMap' es nulo, el c\u00f3digo entra en p\u00e1nico con 'interface conversion: interface {} is nil, not *context.SuciSupiMap'. free5GC AUSF versi\u00f3n 1.4.2 parchea el problema. No hay una soluci\u00f3n alternativa directa a nivel de aplicaci\u00f3n. La recomendaci\u00f3n es aplicar el parche proporcionado o restringir el acceso a la API de AUSF solo a fuentes confiables."}], "lastModified": "2026-03-27T17:06:55.163", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:free5gc:free5gc:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F7D53A8E-777B-4DD7-898E-7EE90ED6D37A", "versionEndExcluding": "1.4.2"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}