{
    "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-2026-32881",
        "tracking": {
            "current_release_date": "2026-03-26T15:06:08.151726Z",
            "generator": {
                "date": "2026-02-17T15:00:00Z",
                "engine": {
                    "name": "V.E.L.M.A",
                    "version": "1.7"
                }
            },
            "id": "CVE-2026-32881",
            "initial_release_date": "2026-03-18T23:09:20.804087Z",
            "revision_history": [
                {
                    "date": "2026-03-18T23:09:20.804087Z",
                    "number": "1",
                    "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (5).| CWES updated (1)."
                },
                {
                    "date": "2026-03-18T23:09:29.645677Z",
                    "number": "2",
                    "summary": "NCSC Score created."
                },
                {
                    "date": "2026-03-19T15:31:05.547896Z",
                    "number": "3",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (5).| CWES updated (1)."
                },
                {
                    "date": "2026-03-20T18:23:25.971219Z",
                    "number": "4",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products created (1).| References created (4).| CWES updated (1)."
                },
                {
                    "date": "2026-03-20T18:23:29.339030Z",
                    "number": "5",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-20T18:23:57.895211Z",
                    "number": "6",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (4).| CWES updated (1)."
                },
                {
                    "date": "2026-03-20T18:24:03.583960Z",
                    "number": "7",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-20T20:39:46.735060Z",
                    "number": "8",
                    "summary": "Unknown change."
                },
                {
                    "date": "2026-03-20T21:41:57.073279Z",
                    "number": "9",
                    "summary": "References created (1)."
                },
                {
                    "date": "2026-03-20T21:59:25.889810Z",
                    "number": "10",
                    "summary": "Source connected.| CVE status created. (valid)| EPSS created."
                },
                {
                    "date": "2026-03-20T21:59:30.416363Z",
                    "number": "11",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-21T13:46:48.101128Z",
                    "number": "12",
                    "summary": "References removed (1)."
                },
                {
                    "date": "2026-03-22T00:52:11.124978Z",
                    "number": "13",
                    "summary": "References created (1)."
                },
                {
                    "date": "2026-03-22T11:25:12.492422Z",
                    "number": "14",
                    "summary": "References removed (1)."
                },
                {
                    "date": "2026-03-23T00:54:21.430094Z",
                    "number": "15",
                    "summary": "References created (1)."
                },
                {
                    "date": "2026-03-23T05:16:19.047411Z",
                    "number": "16",
                    "summary": "References removed (1)."
                },
                {
                    "date": "2026-03-24T06:59:17.049626Z",
                    "number": "17",
                    "summary": "Products created (1).| Product Identifiers created (1).| Exploits created (1)."
                },
                {
                    "date": "2026-03-24T06:59:22.263072Z",
                    "number": "18",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-24T20:56:44.353435Z",
                    "number": "19",
                    "summary": "References created (1)."
                },
                {
                    "date": "2026-03-24T20:56:47.707407Z",
                    "number": "20",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-26T15:02:57.799239Z",
                    "number": "21",
                    "summary": "EPSS updated."
                },
                {
                    "date": "2026-03-26T15:03:02.006017Z",
                    "number": "22",
                    "summary": "NCSC Score updated."
                }
            ],
            "status": "interim",
            "version": "22"
        }
    },
    "product_tree": {
        "branches": [
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/<3.0.5",
                                "product": {
                                    "name": "vers:unknown/<3.0.5",
                                    "product_id": "CSAFPID-5896897",
                                    "product_identification_helper": {
                                        "cpe": "cpe:2.3:a:vshakitskiy:ewe:*:*:*:*:*:*:*:*"
                                    }
                                }
                            },
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/>=0.6.0|<3.0.5",
                                "product": {
                                    "name": "vers:unknown/>=0.6.0|<3.0.5",
                                    "product_id": "CSAFPID-5874278"
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "ewe"
                    }
                ],
                "category": "vendor",
                "name": "vshakitskiy"
            }
        ]
    },
    "vulnerabilities": [
        {
            "cve": "CVE-2026-32881",
            "cwe": {
                "id": "CWE-183",
                "name": "Permissive List of Allowed Inputs"
            },
            "notes": [
                {
                    "category": "description",
                    "text": "## Summary\n\newe's chunked transfer encoding trailer handling merges declared trailer fields into `req.headers` after body parsing, but the denylist only blocks 9 header names. Security-sensitive headers like `authorization`, `cookie`, and `x-forwarded-for` can be injected or overwritten by a malicious client via trailers, potentially bypassing authentication or spoofing proxy-trust headers.\n\n## Impact\n\nWhen `ewe.read_body` processes a chunked request with a `Trailer` header, it calls `handle_trailers` (`ewe/internal/http1.gleam:493`), which merges declared trailer fields into `req.headers` via `request.set_header` (line 517). The `is_forbidden_trailer` denylist (line 534) only blocks 9 header names: `transfer-encoding`, `content-length`, `host`, `cache-control`, `expect`, `max-forwards`, `pragma`, `range`, and `te`.\n\nSecurity-sensitive headers are not blocked, including:\n\n- `authorization` — attacker can inject or overwrite Bearer tokens\n- `cookie` / `set-cookie` — attacker can inject session cookies\n- `proxy-authorization` — attacker can inject proxy credentials\n- `x-forwarded-for`, `x-forwarded-host`, `x-forwarded-proto` — attacker can spoof proxy-trust headers\n- `x-real-ip` — attacker can spoof client IP\n\nA malicious client can inject these headers by declaring them in the `Trailer` request header and including them after the final `0\\r\\n` chunk. If the header already exists (e.g., set by a reverse proxy), `request.set_header` overwrites it. Any application logic that reads these headers after calling `ewe.read_body` — such as authentication middleware, IP-based rate limiting, or session validation — will see the attacker-controlled values.\n\n### Proof of Concept\n\n**Inject an `authorization` header that didn't exist:**\n\n```sh\nprintf 'POST / HTTP/1.1\\r\\nHost: localhost:8080\\r\\nTransfer-Encoding: chunked\\r\\nTrailer: authorization\\r\\n\\r\\n4\\r\\ntest\\r\\n0\\r\\nauthorization: Bearer injected-token\\r\\n\\r\\n' | nc -w 2 localhost 8080\n```\n\n**Overwrite a legitimate `authorization` header set by a proxy:**\n\n```sh\nprintf 'POST / HTTP/1.1\\r\\nHost: localhost:8080\\r\\nAuthorization: Bearer legitimate-token\\r\\nTransfer-Encoding: chunked\\r\\nTrailer: authorization\\r\\n\\r\\n4\\r\\ntest\\r\\n0\\r\\nauthorization: Bearer evil-token\\r\\n\\r\\n' | nc -w 2 localhost 8080\n```\n\n**Inject `x-forwarded-for` to spoof client IP:**\n\n```sh\nprintf 'POST / HTTP/1.1\\r\\nHost: localhost:8080\\r\\nTransfer-Encoding: chunked\\r\\nTrailer: x-forwarded-for\\r\\n\\r\\n4\\r\\ntest\\r\\n0\\r\\nx-forwarded-for: 10.0.0.1\\r\\n\\r\\n' | nc -w 2 localhost 8080\n```\n\n## Patches\n\n- Expand the denylist in `is_forbidden_trailer` to include `authorization`, `cookie`, `set-cookie`, `proxy-authorization`, `x-forwarded-for`, `x-forwarded-host`, `x-forwarded-proto`, `x-real-ip`, and other security-sensitive headers.\n- Alternatively, switch to an allowlist model that only permits explicitly safe trailer field names.",
                    "title": "github - https://github.com/advisories/GHSA-9w88-79f8-m3vp"
                },
                {
                    "category": "description",
                    "text": "## Summary\n\newe's chunked transfer encoding trailer handling merges declared trailer fields into `req.headers` after body parsing, but the denylist only blocks 9 header names. Security-sensitive headers like `authorization`, `cookie`, and `x-forwarded-for` can be injected or overwritten by a malicious client via trailers, potentially bypassing authentication or spoofing proxy-trust headers.\n\n## Impact\n\nWhen `ewe.read_body` processes a chunked request with a `Trailer` header, it calls `handle_trailers` (`ewe/internal/http1.gleam:493`), which merges declared trailer fields into `req.headers` via `request.set_header` (line 517). The `is_forbidden_trailer` denylist (line 534) only blocks 9 header names: `transfer-encoding`, `content-length`, `host`, `cache-control`, `expect`, `max-forwards`, `pragma`, `range`, and `te`.\n\nSecurity-sensitive headers are not blocked, including:\n\n- `authorization` — attacker can inject or overwrite Bearer tokens\n- `cookie` / `set-cookie` — attacker can inject session cookies\n- `proxy-authorization` — attacker can inject proxy credentials\n- `x-forwarded-for`, `x-forwarded-host`, `x-forwarded-proto` — attacker can spoof proxy-trust headers\n- `x-real-ip` — attacker can spoof client IP\n\nA malicious client can inject these headers by declaring them in the `Trailer` request header and including them after the final `0\\r\\n` chunk. If the header already exists (e.g., set by a reverse proxy), `request.set_header` overwrites it. Any application logic that reads these headers after calling `ewe.read_body` — such as authentication middleware, IP-based rate limiting, or session validation — will see the attacker-controlled values.\n\n### Proof of Concept\n\n**Inject an `authorization` header that didn't exist:**\n\n```sh\nprintf 'POST / HTTP/1.1\\r\\nHost: localhost:8080\\r\\nTransfer-Encoding: chunked\\r\\nTrailer: authorization\\r\\n\\r\\n4\\r\\ntest\\r\\n0\\r\\nauthorization: Bearer injected-token\\r\\n\\r\\n' | nc -w 2 localhost 8080\n```\n\n**Overwrite a legitimate `authorization` header set by a proxy:**\n\n```sh\nprintf 'POST / HTTP/1.1\\r\\nHost: localhost:8080\\r\\nAuthorization: Bearer legitimate-token\\r\\nTransfer-Encoding: chunked\\r\\nTrailer: authorization\\r\\n\\r\\n4\\r\\ntest\\r\\n0\\r\\nauthorization: Bearer evil-token\\r\\n\\r\\n' | nc -w 2 localhost 8080\n```\n\n**Inject `x-forwarded-for` to spoof client IP:**\n\n```sh\nprintf 'POST / HTTP/1.1\\r\\nHost: localhost:8080\\r\\nTransfer-Encoding: chunked\\r\\nTrailer: x-forwarded-for\\r\\n\\r\\n4\\r\\ntest\\r\\n0\\r\\nx-forwarded-for: 10.0.0.1\\r\\n\\r\\n' | nc -w 2 localhost 8080\n```\n\n## Patches\n\n- Expand the denylist in `is_forbidden_trailer` to include `authorization`, `cookie`, `set-cookie`, `proxy-authorization`, `x-forwarded-for`, `x-forwarded-host`, `x-forwarded-proto`, `x-real-ip`, and other security-sensitive headers.\n- Alternatively, switch to an allowlist model that only permits explicitly safe trailer field names.",
                    "title": "github - https://api.github.com/advisories/GHSA-9w88-79f8-m3vp"
                },
                {
                    "category": "description",
                    "text": "ewe is a Gleam web server. ewe is a Gleam web server. Versions 0.6.0 through 3.0.4 are vulnerable to authentication bypass or spoofed proxy-trust headers. Chunked transfer encoding trailer handling merges declared trailer fields into req.headers after body parsing, but the denylist only blocks 9 header names.  A malicious client can exploit this by declaring these headers in the Trailer field and appending them after the final chunk, causing request.set_header to overwrite legitimate values (e.g., those set by a reverse proxy). This enables attackers to forge authentication credentials, hijack sessions, bypass IP-based rate limiting, or spoof proxy-trust headers in any downstream middleware that reads headers after ewe.read_body is called. This issue has been fixed in version 3.0.5.",
                    "title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/32xxx/CVE-2026-32881.json"
                },
                {
                    "category": "description",
                    "text": "ewe is a Gleam web server. ewe is a Gleam web server. Versions 0.6.0 through 3.0.4 are vulnerable to authentication bypass or spoofed proxy-trust headers. Chunked transfer encoding trailer handling merges declared trailer fields into req.headers after body parsing, but the denylist only blocks 9 header names.  A malicious client can exploit this by declaring these headers in the Trailer field and appending them after the final chunk, causing request.set_header to overwrite legitimate values (e.g., those set by a reverse proxy). This enables attackers to forge authentication credentials, hijack sessions, bypass IP-based rate limiting, or spoof proxy-trust headers in any downstream middleware that reads headers after ewe.read_body is called. This issue has been fixed in version 3.0.5.",
                    "title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-32881"
                },
                {
                    "category": "other",
                    "text": "0.00188",
                    "title": "EPSS"
                },
                {
                    "category": "other",
                    "text": "3.8",
                    "title": "NCSC Score"
                },
                {
                    "category": "other",
                    "text": "The value of the most recent EPSS score, Exploit code publicly available, There is exploit data available from source Nvd",
                    "title": "NCSC Score top decreasing factors"
                }
            ],
            "product_status": {
                "known_affected": [
                    "CSAFPID-5874278",
                    "CSAFPID-5896897"
                ]
            },
            "references": [
                {
                    "category": "external",
                    "summary": "Source - github",
                    "url": "https://github.com/advisories/GHSA-9w88-79f8-m3vp"
                },
                {
                    "category": "external",
                    "summary": "Source raw - github",
                    "url": "https://api.github.com/advisories/GHSA-9w88-79f8-m3vp"
                },
                {
                    "category": "external",
                    "summary": "Source - github",
                    "url": "https://api.github.com/advisories/GHSA-9w88-79f8-m3vp"
                },
                {
                    "category": "external",
                    "summary": "Source - cveprojectv5",
                    "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/32xxx/CVE-2026-32881.json"
                },
                {
                    "category": "external",
                    "summary": "Source - nvd",
                    "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-32881"
                },
                {
                    "category": "external",
                    "summary": "Source - first",
                    "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; github; nvd",
                    "url": "https://github.com/vshakitskiy/ewe/security/advisories/GHSA-9w88-79f8-m3vp"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; github; nvd",
                    "url": "https://github.com/vshakitskiy/ewe/commit/07dcfd2135fc95f38c17a9d030de3d7efee1ee39"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; github; nvd",
                    "url": "https://github.com/vshakitskiy/ewe/commit/94ab6e7bf7293e987ae98b4daa51ea131c2671ba"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; github; nvd",
                    "url": "https://github.com/vshakitskiy/ewe/releases/tag/v3.0.5"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://github.com/advisories/GHSA-9w88-79f8-m3vp"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-32881"
                }
            ],
            "scores": [
                {
                    "cvss_v3": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
                        "baseScore": 5.3,
                        "baseSeverity": "MEDIUM"
                    },
                    "products": [
                        "CSAFPID-5874278",
                        "CSAFPID-5896897"
                    ]
                }
            ],
            "title": "CVE-2026-32881"
        }
    ]
}