{
    "document": {
        "category": "csaf_base",
        "csaf_version": "2.0",
        "distribution": {
            "tlp": {
                "label": "WHITE"
            }
        },
        "lang": "en",
        "notes": [
            {
                "category": "legal_disclaimer",
                "text": "The Netherlands Cyber Security Center (henceforth: NCSC-NL) maintains this portal to enhance access to its information and vulnerabilities. The use of this information is subject to the following terms and conditions:\n\nThe vulnerabilities disclosed in this portal are gathered by NCSC-NL from a variety of open sources, which the user can retrieve from other platforms. NCSC-NL makes every reasonable effort to ensure that the content of this portal is kept up to date, and that it is accurate and complete. Nevertheless, NCSC-NL cannot entirely rule out the possibility of errors, and therefore cannot give any warranty in respect of its completeness, accuracy or real-time keeping up-to-date. NCSC-NL does not control nor guarantee the accuracy, relevance, timeliness or completeness of information obtained from these external sources. The vulnerabilities disclosed in this portal are intended solely for the convenience of professional parties to take appropriate measures to manage the risks posed to the cybersecurity. No rights can be derived from the information provided therein.\n\nNCSC-NL and the Kingdom of the Netherlands assume no legal liability or responsibility for any damage resulting from either the use or inability of use of the vulnerabilities disclosed in this portal. This includes damage resulting from the inaccuracy of incompleteness of the information contained in it.\nThe information on this page is subject to Dutch law. All disputes related to or arising from the use of this portal regarding the disclosure of vulnerabilities will be submitted to the competent court in The Hague. This choice of means also applies to the court in summary proceedings."
            }
        ],
        "publisher": {
            "category": "coordinator",
            "contact_details": "cert@ncsc.nl",
            "name": "National Cyber Security Centre",
            "namespace": "https://www.ncsc.nl/"
        },
        "title": "CVE-2026-33191",
        "tracking": {
            "current_release_date": "2026-03-25T18:15:54.559980Z",
            "generator": {
                "date": "2026-02-17T15:00:00Z",
                "engine": {
                    "name": "V.E.L.M.A",
                    "version": "1.7"
                }
            },
            "id": "CVE-2026-33191",
            "initial_release_date": "2026-03-18T20:44:17.532892Z",
            "revision_history": [
                {
                    "date": "2026-03-18T20:44:17.532892Z",
                    "number": "1",
                    "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (3).| CWES updated (1)."
                },
                {
                    "date": "2026-03-18T20:44:29.750842Z",
                    "number": "2",
                    "summary": "NCSC Score created."
                },
                {
                    "date": "2026-03-19T11:39:55.095168Z",
                    "number": "3",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (3).| CWES updated (1)."
                },
                {
                    "date": "2026-03-19T11:40:06.366700Z",
                    "number": "4",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-20T18:27:41.118105Z",
                    "number": "5",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products connected (1).| References created (2).| CWES updated (1)."
                },
                {
                    "date": "2026-03-20T18:27:45.343422Z",
                    "number": "6",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-20T18:28:45.735363Z",
                    "number": "7",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (2).| CWES updated (1)."
                },
                {
                    "date": "2026-03-20T18:28:50.312224Z",
                    "number": "8",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-20T20:39:21.702150Z",
                    "number": "9",
                    "summary": "Unknown change."
                },
                {
                    "date": "2026-03-20T21:41:22.664438Z",
                    "number": "10",
                    "summary": "References created (2)."
                },
                {
                    "date": "2026-03-20T21:58:56.597443Z",
                    "number": "11",
                    "summary": "Source connected.| CVE status created. (valid)| EPSS created."
                },
                {
                    "date": "2026-03-20T21:59:01.422481Z",
                    "number": "12",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-24T10:18:45.159171Z",
                    "number": "13",
                    "summary": "CVSS created.| Products created (1).| Product Identifiers created (1)."
                },
                {
                    "date": "2026-03-24T10:18:48.473056Z",
                    "number": "14",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-25T18:13:04.076260Z",
                    "number": "15",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products created (1).| References created (4).| CWES updated (1)."
                },
                {
                    "date": "2026-03-25T18:13:06.357789Z",
                    "number": "16",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-25T18:13:34.361484Z",
                    "number": "17",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| References created (4)."
                }
            ],
            "status": "interim",
            "version": "17"
        }
    },
    "product_tree": {
        "branches": [
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/<1.4.2",
                                "product": {
                                    "name": "vers:unknown/<1.4.2",
                                    "product_id": "CSAFPID-5874539"
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "Free5gc"
                    },
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/<1.4.2",
                                "product": {
                                    "name": "vers:unknown/<1.4.2",
                                    "product_id": "CSAFPID-5897414",
                                    "product_identification_helper": {
                                        "cpe": "cpe:2.3:a:free5gc:udm:*:*:*:*:*:go:*:*"
                                    }
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/>=0|<1.4.2",
                                "product": {
                                    "name": "vers:unknown/>=0|<1.4.2",
                                    "product_id": "CSAFPID-5907216"
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "udm"
                    }
                ],
                "category": "vendor",
                "name": "free5GC"
            }
        ]
    },
    "vulnerabilities": [
        {
            "cve": "CVE-2026-33191",
            "cwe": {
                "id": "CWE-158",
                "name": "Improper Neutralization of Null Byte or NUL Character"
            },
            "notes": [
                {
                    "category": "description",
                    "text": "**Impact**  \nThis is an Improper Input Validation vulnerability with Denial of Service and Injection implications.  \n- **Security Impact**: 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.  \n- **Functional Impact**: 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.  \n- **Affected Parties**: All deployments of free5GC v4.0.1 using the UDM Nudm_SDM service with endpoints that include path parameters (e.g., `/nudm-sdm/v2/{supi}/am-data`).\n\n**Patches**  \nYes, the issue has been patched.  \nThe fix is implemented in PR free5gc/udm#79.  \nUsers should upgrade to the next release of free5GC that includes this commit.\n\n**Workarounds**  \nThere is no direct workaround at the application level. The recommendation is to apply the provided patch or implement API gateway-level validation to reject requests containing null bytes in path parameters before they reach UDM.",
                    "title": "github - https://github.com/advisories/GHSA-p9hg-pq3q-v9gv"
                },
                {
                    "category": "description",
                    "text": "**Impact**  \nThis is an Improper Input Validation vulnerability with Denial of Service and Injection implications.  \n- **Security Impact**: 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.  \n- **Functional Impact**: 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.  \n- **Affected Parties**: All deployments of free5GC v4.0.1 using the UDM Nudm_SDM service with endpoints that include path parameters (e.g., `/nudm-sdm/v2/{supi}/am-data`).\n\n**Patches**  \nYes, the issue has been patched.  \nThe fix is implemented in PR free5gc/udm#79.  \nUsers should upgrade to the next release of free5GC that includes this commit.\n\n**Workarounds**  \nThere is no direct workaround at the application level. The recommendation is to apply the provided patch or implement API gateway-level validation to reject requests containing null bytes in path parameters before they reach UDM.",
                    "title": "github - https://api.github.com/advisories/GHSA-p9hg-pq3q-v9gv"
                },
                {
                    "category": "description",
                    "text": "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.",
                    "title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/33xxx/CVE-2026-33191.json"
                },
                {
                    "category": "description",
                    "text": "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.",
                    "title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-33191"
                },
                {
                    "category": "description",
                    "text": "**Impact**  \nThis is an Improper Input Validation vulnerability with Denial of Service and Injection implications.  \n- **Security Impact**: 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.  \n- **Functional Impact**: 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.  \n- **Affected Parties**: All deployments of free5GC v4.0.1 using the UDM Nudm_SDM service with endpoints that include path parameters (e.g., `/nudm-sdm/v2/{supi}/am-data`).\n\n**Patches**  \nYes, the issue has been patched.  \nThe fix is implemented in PR free5gc/udm#79.  \nUsers should upgrade to the next release of free5GC that includes this commit.\n\n**Workarounds**  \nThere is no direct workaround at the application level. The recommendation is to apply the provided patch or implement API gateway-level validation to reject requests containing null bytes in path parameters before they reach UDM.",
                    "title": "osv - https://www.googleapis.com/download/storage/v1/b/osv-vulnerabilities/o/Go%2FGHSA-p9hg-pq3q-v9gv.json?alt=media"
                },
                {
                    "category": "description",
                    "text": "free5GC UDM vulnerable to null byte injection in URL path parameters causing 500 Internal Server Error in github.com/free5gc/udm",
                    "title": "osv - https://www.googleapis.com/download/storage/v1/b/osv-vulnerabilities/o/Go%2FGO-2026-4763.json?alt=media"
                },
                {
                    "category": "other",
                    "text": "0.0023",
                    "title": "EPSS"
                },
                {
                    "category": "other",
                    "text": "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",
                    "title": "CVSSV4"
                },
                {
                    "category": "other",
                    "text": "8.7",
                    "title": "CVSSV4 base score"
                },
                {
                    "category": "other",
                    "text": "4.4",
                    "title": "NCSC Score"
                },
                {
                    "category": "other",
                    "text": "Is related to (a version of) an uncommon product, The value of the most recent CVSS (V3) score",
                    "title": "NCSC Score top decreasing factors"
                }
            ],
            "product_status": {
                "known_affected": [
                    "CSAFPID-5874539",
                    "CSAFPID-5897414",
                    "CSAFPID-5907216"
                ]
            },
            "references": [
                {
                    "category": "external",
                    "summary": "Source - github",
                    "url": "https://github.com/advisories/GHSA-p9hg-pq3q-v9gv"
                },
                {
                    "category": "external",
                    "summary": "Source raw - github",
                    "url": "https://api.github.com/advisories/GHSA-p9hg-pq3q-v9gv"
                },
                {
                    "category": "external",
                    "summary": "Source - github",
                    "url": "https://api.github.com/advisories/GHSA-p9hg-pq3q-v9gv"
                },
                {
                    "category": "external",
                    "summary": "Source - cveprojectv5",
                    "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/33xxx/CVE-2026-33191.json"
                },
                {
                    "category": "external",
                    "summary": "Source - nvd",
                    "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-33191"
                },
                {
                    "category": "external",
                    "summary": "Source - first",
                    "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0"
                },
                {
                    "category": "external",
                    "summary": "Source - osv",
                    "url": "https://www.googleapis.com/download/storage/v1/b/osv-vulnerabilities/o/Go%2FGHSA-p9hg-pq3q-v9gv.json?alt=media"
                },
                {
                    "category": "external",
                    "summary": "Source - osv",
                    "url": "https://www.googleapis.com/download/storage/v1/b/osv-vulnerabilities/o/Go%2FGO-2026-4763.json?alt=media"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; github; nvd; osv",
                    "url": "https://github.com/free5gc/free5gc/security/advisories/GHSA-p9hg-pq3q-v9gv"
                },
                {
                    "category": "external",
                    "summary": "Reference - github; osv",
                    "url": "https://github.com/free5gc/udm/pull/79"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://github.com/advisories/GHSA-p9hg-pq3q-v9gv"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; github; nvd; osv",
                    "url": "https://github.com/free5gc/udm/commit/88de9fa74a1b3f3522e53b4cfa2d184712ffa4ee"
                },
                {
                    "category": "external",
                    "summary": "Reference - github; osv",
                    "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33191"
                }
            ],
            "scores": [
                {
                    "cvss_v3": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H",
                        "baseScore": 8.6,
                        "baseSeverity": "HIGH"
                    },
                    "products": [
                        "CSAFPID-5874539",
                        "CSAFPID-5897414",
                        "CSAFPID-5907216"
                    ]
                }
            ],
            "title": "CVE-2026-33191"
        }
    ]
}