{
    "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-2026-2833",
        "tracking": {
            "current_release_date": "2026-03-23T03:14:36.422544Z",
            "generator": {
                "date": "2026-02-17T15:00:00Z",
                "engine": {
                    "name": "V.E.L.M.A",
                    "version": "1.7"
                }
            },
            "id": "CVE-2026-2833",
            "initial_release_date": "2026-03-04T23:38:36.635261Z",
            "revision_history": [
                {
                    "date": "2026-03-04T23:38:36.635261Z",
                    "number": "1",
                    "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products created (1).| References created (1).| CWES updated (1)."
                },
                {
                    "date": "2026-03-04T23:38:40.981369Z",
                    "number": "2",
                    "summary": "NCSC Score created."
                },
                {
                    "date": "2026-03-05T00:25:02.176383Z",
                    "number": "3",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (1).| CWES updated (1)."
                },
                {
                    "date": "2026-03-05T00:25:05.915379Z",
                    "number": "4",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-05T14:13:09.757488Z",
                    "number": "5",
                    "summary": "Source created.| CVE status created. (valid)| EPSS created."
                },
                {
                    "date": "2026-03-05T21:40:05.232587Z",
                    "number": "6",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (4).| CWES updated (1)."
                },
                {
                    "date": "2026-03-05T21:40:07.622761Z",
                    "number": "7",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-06T19:38:49.486510Z",
                    "number": "8",
                    "summary": "Unknown change."
                },
                {
                    "date": "2026-03-06T19:38:54.185838Z",
                    "number": "9",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-09T21:47:13.508740Z",
                    "number": "10",
                    "summary": "Description removed for source.| Description created for source."
                },
                {
                    "date": "2026-03-09T21:47:21.237732Z",
                    "number": "11",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-12T15:25:34.355601Z",
                    "number": "12",
                    "summary": "CVSS created.| Products created (1).| Product Identifiers created (1)."
                },
                {
                    "date": "2026-03-12T15:25:44.322673Z",
                    "number": "13",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-20T09:37:47.780199Z",
                    "number": "14",
                    "summary": "Source connected.| CVE status created. (valid)| EPSS created."
                }
            ],
            "status": "interim",
            "version": "14"
        }
    },
    "product_tree": {
        "branches": [
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:semver/<0.8.0",
                                "product": {
                                    "name": "vers:semver/<0.8.0",
                                    "product_id": "CSAFPID-5759431"
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "https://github.com/cloudflare/pingora"
                    },
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/<0.8.0",
                                "product": {
                                    "name": "vers:unknown/<0.8.0",
                                    "product_id": "CSAFPID-5810444",
                                    "product_identification_helper": {
                                        "cpe": "cpe:2.3:a:cloudflare:pingora:*:*:*:*:*:*:*:*"
                                    }
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "pingora"
                    }
                ],
                "category": "vendor",
                "name": "Cloudflare"
            }
        ]
    },
    "vulnerabilities": [
        {
            "cve": "CVE-2026-2833",
            "cwe": {
                "id": "CWE-444",
                "name": "Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')"
            },
            "notes": [
                {
                    "category": "description",
                    "text": "An HTTP request smuggling vulnerability (CWE-444) was found in Pingora's handling of HTTP/1.1 connection upgrades. The issue occurs when a Pingora proxy reads a request containing an Upgrade header, causing the proxy to pass through the rest of the bytes on the connection to a backend before the backend has accepted the upgrade. An attacker can thus directly forward a malicious payload after a request with an Upgrade header to that backend in a way that may be interpreted as a subsequent request header, bypassing proxy-level security controls and enabling cross-user session hijacking.\n\nImpact\n\nThis vulnerability primarily affects standalone Pingora deployments where a Pingora proxy is exposed to external traffic. An attacker could exploit this to:\n\n  *  Bypass proxy-level ACL controls and WAF logic\n\n\n\n\n  *  Poison caches and upstream connections, causing subsequent requests from legitimate users to receive responses intended for smuggled requests\n\n\n\n\n  *  Perform cross-user attacks by hijacking sessions or smuggling requests that appear to originate from the trusted proxy IP\n\n\n\n\nCloudflare's CDN infrastructure was not affected by this vulnerability, as ingress proxies in the CDN stack maintain proper HTTP parsing boundaries and do not prematurely switch to upgraded connection forwarding mode.\n\n\nMitigation:\n\nPingora users should upgrade to Pingora v0.8.0 or higher\n\n\nAs a workaround, users may return an error on requests with the Upgrade header present in their request filter logic in order to stop processing bytes beyond the request header and disable downstream connection reuse.",
                    "title": "cveprojectv5 - https://www.cve.org/CVERecord?id=CVE-2026-2833"
                },
                {
                    "category": "description",
                    "text": "An HTTP request smuggling vulnerability (CWE-444) was found in Pingora's handling of HTTP/1.1 connection upgrades. The issue occurs when a Pingora proxy reads a request containing an Upgrade header, causing the proxy to pass through the rest of the bytes on the connection to a backend before the backend has accepted the upgrade. An attacker can thus directly forward a malicious payload after a request with an Upgrade header to that backend in a way that may be interpreted as a subsequent request header, bypassing proxy-level security controls and enabling cross-user session hijacking.\n\nImpact\n\nThis vulnerability primarily affects standalone Pingora deployments where a Pingora proxy is exposed to external traffic. An attacker could exploit this to:\n\n  *  Bypass proxy-level ACL controls and WAF logic\n\n\n\n\n  *  Poison caches and upstream connections, causing subsequent requests from legitimate users to receive responses intended for smuggled requests\n\n\n\n\n  *  Perform cross-user attacks by hijacking sessions or smuggling requests that appear to originate from the trusted proxy IP\n\n\n\n\nCloudflare's CDN infrastructure was not affected by this vulnerability, as ingress proxies in the CDN stack maintain proper HTTP parsing boundaries and do not prematurely switch to upgraded connection forwarding mode.\n\n\nMitigation:\n\nPingora users should upgrade to Pingora v0.8.0 or higher\n\n\nAs a workaround, users may return an error on requests with the Upgrade header present in their request filter logic in order to stop processing bytes beyond the request header and disable downstream connection reuse.",
                    "title": "nvd - https://nvd.nist.gov/vuln/detail/CVE-2026-2833"
                },
                {
                    "category": "description",
                    "text": "### Impact\nPingora versions prior to 0.8.0 would immediately forward bytes following a request with an Upgrade header to the backend, without waiting for a 101 Switching Protocols response. This allows an attacker to smuggle requests to the backend and bypass proxy-level security controls.\n\nThis vulnerability primarily affects standalone Pingora deployments where a Pingora proxy is exposed to external traffic. An attacker could exploit this to bypass proxy-level ACL controls and WAF logic, poison caches and upstream connections, or perform cross-user attacks by hijacking sessions.\n\nNote: Cloudflare customers and Cloudflare's CDN infrastructure were not affected by this vulnerability, as ingress proxies in the CDN stack maintain proper HTTP parsing boundaries and do not prematurely switch to upgraded connection forwarding mode.\n\n### Patches\nPingora users should upgrade to Pingora v0.8.0 or higher, which fixes this issue by only switching connection modes after receiving a 101 Switching Protocols response from the backend (hash 824bdeefc61e121cc8861de1b35e8e8f39026ecd). Without a 101 response, subsequent bytes continue to be parsed as HTTP requests.\n\n### Workarounds\nAs a workaround, users may return an error on requests with the Upgrade header present in their request filter logic in order to stop processing bytes beyond the request header and disable downstream connection reuse.\n\n### References\nSee [CVE-2026-2833](https://www.cve.org/cverecord?id=CVE-2026-2833) and the [Cloudflare blog post](https://blog.cloudflare.com/pingora-oss-smuggling-vulnerabilities/) for more details.\n\n### Credits\nDisclosed responsibly by Rajat Raghav (@xclow3n) through the Cloudflare [Bug Bounty Program](https://www.cloudflare.com/disclosure/).",
                    "title": "github - https://github.com/advisories/GHSA-xq2h-p299-vjwv"
                },
                {
                    "category": "other",
                    "text": "0.00041",
                    "title": "EPSS"
                },
                {
                    "category": "other",
                    "text": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N",
                    "title": "CVSSV4"
                },
                {
                    "category": "other",
                    "text": "9.3",
                    "title": "CVSSV4 base score"
                },
                {
                    "category": "other",
                    "text": "4.4",
                    "title": "NCSC Score"
                }
            ],
            "product_status": {
                "known_affected": [
                    "CSAFPID-5759431",
                    "CSAFPID-5810444"
                ]
            },
            "references": [
                {
                    "category": "external",
                    "summary": "Source - cveprojectv5",
                    "url": "https://www.cve.org/CVERecord?id=CVE-2026-2833"
                },
                {
                    "category": "external",
                    "summary": "Source raw - cveprojectv5",
                    "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/2xxx/CVE-2026-2833.json"
                },
                {
                    "category": "external",
                    "summary": "Source - nvd",
                    "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-2833"
                },
                {
                    "category": "external",
                    "summary": "Source raw - nvd",
                    "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-2833"
                },
                {
                    "category": "external",
                    "summary": "Source - first",
                    "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-2833"
                },
                {
                    "category": "external",
                    "summary": "Source raw - first",
                    "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0"
                },
                {
                    "category": "external",
                    "summary": "Source - github",
                    "url": "https://github.com/advisories/GHSA-xq2h-p299-vjwv"
                },
                {
                    "category": "external",
                    "summary": "Source raw - github",
                    "url": "https://api.github.com/advisories/GHSA-xq2h-p299-vjwv"
                },
                {
                    "category": "external",
                    "summary": "Source - first",
                    "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "https://github.com/cloudflare/pingora"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://github.com/cloudflare/pingora/security/advisories/GHSA-xq2h-p299-vjwv"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-2833"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://rustsec.org/advisories/RUSTSEC-2026-0033.html"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://github.com/advisories/GHSA-xq2h-p299-vjwv"
                }
            ],
            "scores": [
                {
                    "cvss_v3": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
                        "baseScore": 9.1,
                        "baseSeverity": "CRITICAL"
                    },
                    "products": [
                        "CSAFPID-5759431",
                        "CSAFPID-5810444"
                    ]
                }
            ],
            "title": "CVE-2026-2833"
        }
    ]
}