CVE-2026-33191

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-33191", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-03-17T22:16:36.721Z", "datePublished": "2026-03-20T07:54:26.539Z", "dateUpdated": "2026-03-20T19:36:09.548Z"}, "containers": {"cna": {"title": "free5GC UDM vulnerable to null byte injection in URL path parameters causing 500 Internal Server Error", "problemTypes": [{"descriptions": [{"cweId": "CWE-158", "lang": "en", "description": "CWE-158: Improper Neutralization of Null Byte or NUL Character", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-248", "lang": "en", "description": "CWE-248: Uncaught Exception", "type": "CWE"}]}], "metrics": [{"cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 8.7, "baseSeverity": "HIGH", "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", "version": "4.0"}}], "references": [{"name": "https://github.com/free5gc/free5gc/security/advisories/GHSA-p9hg-pq3q-v9gv", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/free5gc/free5gc/security/advisories/GHSA-p9hg-pq3q-v9gv"}, {"name": "https://github.com/free5gc/udm/commit/88de9fa74a1b3f3522e53b4cfa2d184712ffa4ee", "tags": ["x_refsource_MISC"], "url": "https://github.com/free5gc/udm/commit/88de9fa74a1b3f3522e53b4cfa2d184712ffa4ee"}], "affected": [{"vendor": "free5gc", "product": "free5gc", "versions": [{"version": "< 1.4.2", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-03-20T07:54:26.539Z"}, "descriptions": [{"lang": "en", "value": "Free5GC is an open-source Linux Foundation project for 5th generation (5G) mobile core networks. Versions prior to 1.4.2\nare vulnerable to null byte injection in URL path parameters. A remote attacker can inject null bytes (URL-encoded as %00) into the supi path parameter of the UDM's Nudm_SubscriberDataManagement API. This causes URL parsing failure in Go's net/url package with the error \"invalid control character in URL\", resulting in a 500 Internal Server Error. This null byte injection vulnerability can be exploited for denial of service attacks. When the supi parameter contains null characters, the UDM attempts to construct a URL for UDR that includes these control characters. Go's URL parser rejects them, causing the request to fail with 500 instead of properly validating input and returning 400 Bad Request. This issue has been fixed in version 1.4.2."}], "source": {"advisory": "GHSA-p9hg-pq3q-v9gv", "discovery": "UNKNOWN"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-03-20T19:35:49.317638Z", "id": "CVE-2026-33191", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-03-20T19:36:09.548Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-33191", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-03-20T19:35:49.317638Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-03-20T19:35:59.504Z"}}], "cna": {"title": "free5GC UDM vulnerable to null byte injection in URL path parameters causing 500 Internal Server Error", "source": {"advisory": "GHSA-p9hg-pq3q-v9gv", "discovery": "UNKNOWN"}, "metrics": [{"cvssV4_0": {"version": "4.0", "baseScore": 8.7, "attackVector": "NETWORK", "baseSeverity": "HIGH", "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", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "NONE"}}], "affected": [{"vendor": "free5gc", "product": "free5gc", "versions": [{"status": "affected", "version": "< 1.4.2"}]}], "references": [{"url": "https://github.com/free5gc/free5gc/security/advisories/GHSA-p9hg-pq3q-v9gv", "name": "https://github.com/free5gc/free5gc/security/advisories/GHSA-p9hg-pq3q-v9gv", "tags": ["x_refsource_CONFIRM"]}, {"url": "https://github.com/free5gc/udm/commit/88de9fa74a1b3f3522e53b4cfa2d184712ffa4ee", "name": "https://github.com/free5gc/udm/commit/88de9fa74a1b3f3522e53b4cfa2d184712ffa4ee", "tags": ["x_refsource_MISC"]}], "descriptions": [{"lang": "en", "value": "Free5GC is an open-source Linux Foundation project for 5th generation (5G) mobile core networks. Versions prior to 1.4.2\nare vulnerable to null byte injection in URL path parameters. A remote attacker can inject null bytes (URL-encoded as %00) into the supi path parameter of the UDM's Nudm_SubscriberDataManagement API. This causes URL parsing failure in Go's net/url package with the error \"invalid control character in URL\", resulting in a 500 Internal Server Error. This null byte injection vulnerability can be exploited for denial of service attacks. When the supi parameter contains null characters, the UDM attempts to construct a URL for UDR that includes these control characters. Go's URL parser rejects them, causing the request to fail with 500 instead of properly validating input and returning 400 Bad Request. This issue has been fixed in version 1.4.2."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-158", "description": "CWE-158: Improper Neutralization of Null Byte or NUL Character"}]}, {"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-248", "description": "CWE-248: Uncaught Exception"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-03-20T07:54:26.539Z"}}}, "cveMetadata": {"cveId": "CVE-2026-33191", "state": "PUBLISHED", "dateUpdated": "2026-03-20T19:36:09.548Z", "dateReserved": "2026-03-17T22:16:36.721Z", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "datePublished": "2026-03-20T07:54:26.539Z", "assignerShortName": "GitHub_M"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"product": "free5gc", "vendor": "free5gc", "versions": [{"status": "affected", "version": "< 1.4.2"}]}], "source": "security-advisories@github.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:free5gc:udm:*:*:*:*:*:go:*:*", "matchCriteriaId": "C4C4212B-95F4-49DD-B6DA-F6DF4D8D7257", "versionEndExcluding": "1.4.2", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Free5GC is an open-source Linux Foundation project for 5th generation (5G) mobile core networks. Versions prior to 1.4.2\nare vulnerable to null byte injection in URL path parameters. A remote attacker can inject null bytes (URL-encoded as %00) into the supi path parameter of the UDM's Nudm_SubscriberDataManagement API. This causes URL parsing failure in Go's net/url package with the error \"invalid control character in URL\", resulting in a 500 Internal Server Error. This null byte injection vulnerability can be exploited for denial of service attacks. When the supi parameter contains null characters, the UDM attempts to construct a URL for UDR that includes these control characters. Go's URL parser rejects them, causing the request to fail with 500 instead of properly validating input and returning 400 Bad Request. This issue has been fixed in version 1.4.2."}, {"lang": "es", "value": "Free5GC es un proyecto de c\u00f3digo abierto de la Linux Foundation para redes centrales m\u00f3viles de quinta generaci\u00f3n (5G). Las versiones anteriores a la 1.4.2 son vulnerables a la inyecci\u00f3n de bytes nulos en los par\u00e1metros de ruta de URL. Un atacante remoto puede inyectar bytes nulos (codificados en URL como %00) en el par\u00e1metro de ruta supi de la API Nudm_SubscriberDataManagement del UDM. Esto causa un fallo en el an\u00e1lisis de URL en el paquete net/url de Go con el error 'invalid control character in URL', lo que resulta en un error 500 Internal Server Error. Esta vulnerabilidad de inyecci\u00f3n de bytes nulos puede ser explotada para ataques de denegaci\u00f3n de servicio. Cuando el par\u00e1metro supi contiene caracteres nulos, el UDM intenta construir una URL para UDR que incluye estos caracteres de control. El analizador de URL de Go los rechaza, lo que provoca que la solicitud falle con 500 en lugar de validar correctamente la entrada y devolver 400 Bad Request. Este problema ha sido solucionado en la versi\u00f3n 1.4.2."}], "id": "CVE-2026-33191", "lastModified": "2026-06-17T10:37:06.163", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 8.6, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 4.0, "source": "nvd@nist.gov", "type": "Primary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 8.7, "baseSeverity": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "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", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-33191", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-03-20T19:35:49.317638Z", "version": "2.0.3"}}]}, "published": "2026-03-20T08:16:12.597", "references": [{"source": "security-advisories@github.com", "tags": ["Patch", "Vendor Advisory"], "url": "https://github.com/free5gc/free5gc/security/advisories/GHSA-p9hg-pq3q-v9gv"}, {"source": "security-advisories@github.com", "tags": ["Patch"], "url": "https://github.com/free5gc/udm/commit/88de9fa74a1b3f3522e53b4cfa2d184712ffa4ee"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-158"}, {"lang": "en", "value": "CWE-248"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,1.4.2)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "free5gc", "source": "cna", "vendor": "free5gc"}, "product": "free5gc", "vendor": "free5gc"}], "analysis": {"en": {"generated_at": "2026-03-23T19:51:48.247979+00:00", "value": {"mitigation_remediation": ["Apply the official upgrade to free5GC version 1.4.2 or later, which fixes the null byte handling in UDM."], "summary": {"action": "Immediate Patch", "impact": "Denial of Service"}, "threat_synthesis": {"affected_systems": "The vulnerable component is free5GC's UDM module. All releases prior to version 1.4.2 contain the flaw. The vulnerability lies in the path parameter handling used when UDM contacts the User Data Repository (UDR) via the Nudm_SubscriberDataManagement API. Users running any of the affected free5GC versions on Linux-based 5G core networks are at risk.", "description_and_impact": "A null byte injection vulnerability in the free5GC User Data Management (UDM) service allows an attacker to insert URL\u2011encoded null bytes (%00) into the supi path parameter of the Nudm_SubscriberDataManagement API. This causes Go's net/url package to reject the request with an \"invalid control character in URL\" error, resulting in a 500 Internal Server Error instead of a proper 400 Bad Request. The effect is a denial of service, as legitimate requests to UDM can be repeatedly denied, impacting service availability.", "risk_and_exploitability": "The CVSS score of 8.7 reflects a high severity for denial of service. The EPSS score of less than 1% indicates a low likelihood of widespread exploitation at present. The vulnerability is not listed in the CISA KEV catalog. A remote attacker can exploit this by sending a crafted HTTP request containing a null byte in the supi parameter to the UDM's API endpoint. The CVE description does not state whether authentication is required, so the access requirement remains uncertain; however, the mechanics of the attack do not rely on privileged input."}}}}, "created": "2026-03-20T10:36:50.446898+00:00", "updated": "2026-03-25T14:30:07.478578+00:00", "vendors": ["free5gc", "free5gc$PRODUCT$free5gc"]}