{
"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-2026-27898",
"tracking": {
"current_release_date": "2026-03-23T03:05:16.514763Z",
"generator": {
"date": "2026-02-17T15:00:00Z",
"engine": {
"name": "V.E.L.M.A",
"version": "1.7"
}
},
"id": "CVE-2026-27898",
"initial_release_date": "2026-03-04T20:39:47.525712Z",
"revision_history": [
{
"date": "2026-03-04T20:39:47.525712Z",
"number": "1",
"summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (2).| CWES updated (1)."
},
{
"date": "2026-03-04T20:39:50.425055Z",
"number": "2",
"summary": "NCSC Score created."
},
{
"date": "2026-03-04T22:25:50.518270Z",
"number": "3",
"summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (1).| CWES updated (1)."
},
{
"date": "2026-03-04T22:25:54.055935Z",
"number": "4",
"summary": "NCSC Score updated."
},
{
"date": "2026-03-04T22:40:01.285688Z",
"number": "5",
"summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products connected (1).| References created (1).| CWES updated (1)."
},
{
"date": "2026-03-04T22:40:06.115851Z",
"number": "6",
"summary": "NCSC Score updated."
},
{
"date": "2026-03-05T11:06:16.624146Z",
"number": "7",
"summary": "Source connected.| CVE status created. (valid)| Products connected (2).| References created (6)."
},
{
"date": "2026-03-05T11:06:18.822098Z",
"number": "8",
"summary": "NCSC Score updated."
},
{
"date": "2026-03-05T12:30:36.317955Z",
"number": "9",
"summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (3).| CWES updated (1).| Vendor_assessment created."
},
{
"date": "2026-03-05T12:30:38.413557Z",
"number": "10",
"summary": "NCSC Score updated."
},
{
"date": "2026-03-05T14:14:01.218468Z",
"number": "11",
"summary": "Source created.| CVE status created. (valid)| EPSS created."
},
{
"date": "2026-03-05T14:14:04.067419Z",
"number": "12",
"summary": "NCSC Score updated."
},
{
"date": "2026-03-05T16:39:45.180290Z",
"number": "13",
"summary": "Unknown change."
},
{
"date": "2026-03-06T20:26:31.132020Z",
"number": "14",
"summary": "Products connected (1).| Product Identifiers created (1)."
},
{
"date": "2026-03-06T20:26:35.593283Z",
"number": "15",
"summary": "NCSC Score updated."
},
{
"date": "2026-03-20T09:39:31.983876Z",
"number": "16",
"summary": "Source connected.| CVE status created. (valid)| EPSS created."
},
{
"date": "2026-03-20T09:39:34.869929Z",
"number": "17",
"summary": "NCSC Score updated."
}
],
"status": "interim",
"version": "17"
}
},
"product_tree": {
"branches": [
{
"branches": [
{
"branches": [
{
"category": "product_version_range",
"name": "vers:unknown/<1.35.0",
"product": {
"name": "vers:unknown/<1.35.0",
"product_id": "CSAFPID-5761788"
}
},
{
"category": "product_version_range",
"name": "vers:unknown/<1.35.4",
"product": {
"name": "vers:unknown/<1.35.4",
"product_id": "CSAFPID-5761789"
}
}
],
"category": "product_name",
"name": "Vaultwarden"
}
],
"category": "vendor",
"name": "Open Source"
},
{
"branches": [
{
"branches": [
{
"category": "product_version_range",
"name": "vers:unknown/<1.35.4",
"product": {
"name": "vers:unknown/<1.35.4",
"product_id": "CSAFPID-5759412",
"product_identification_helper": {
"cpe": "cpe:2.3:a:dani-garcia:vaultwarden:*:*:*:*:*:*:*:*"
}
}
}
],
"category": "product_name",
"name": "vaultwarden"
}
],
"category": "vendor",
"name": "dani-garcia"
}
]
},
"vulnerabilities": [
{
"cve": "CVE-2026-27898",
"cwe": {
"id": "CWE-639",
"name": "Authorization Bypass Through User-Controlled Key"
},
"notes": [
{
"category": "description",
"text": "## Summary\n\nIn the test environment, it was confirmed that an authenticated regular user can specify another user’s `cipher_id` and call:\n\n```\nPUT /api/ciphers/{id}/partial\n```\n\nEven though the standard retrieval API correctly denies access to that cipher, the partial update endpoint returns **200 OK** and exposes `cipherDetails` (including `name`, `notes`, `data`, `secureNote`, etc.).\n\n\n\n## Description\n\n`put_cipher_partial` retrieves the target Cipher but does **not perform ownership or access control checks** before returning `to_json`.\nAuthorization checks present in the normal update API are missing here.\nsrc/api/core/ciphers.rs:717\n\n```rust\nlet Some(cipher) = Cipher::find_by_uuid(&cipher_id, &conn).await else {\n err!(\"Cipher doesn't exist\")\n};\n\nif let Some(ref folder_id) = data.folder_id {\n if Folder::find_by_uuid_and_user(folder_id, &headers.user.uuid, &conn).await.is_none() {\n err!(\"Invalid folder\", \"Folder does not exist or belongs to another user\");\n }\n}\n\n// Move cipher\ncipher.move_to_folder(data.folder_id.clone(), &headers.user.uuid, &conn).await?;\n\n// Update favorite\ncipher.set_favorite(Some(data.favorite), &headers.user.uuid, &conn).await?;\n\nOk(Json(cipher.to_json(&headers.host, &headers.user.uuid, None, CipherSyncType::User, &conn).await?))\n```\n\nBy comparison, the standard update API includes an explicit authorization check:\nsrc/api/core/ciphers.rs:688\n\n```rust\nif !cipher.is_write_accessible_to_user(&headers.user.uuid, &conn).await {\n err!(\"Cipher is not write accessible\")\n}\n```\n\nThe `to_json` method does not abort processing when access restrictions are not met; instead, it proceeds to construct and return a detailed response.\nsrc/db/models/cipher.rs:175\n\n```rust\nlet (read_only, hide_passwords, _) = if sync_type == CipherSyncType::User {\n match self.get_access_restrictions(user_uuid, cipher_sync_data, conn).await {\n Some((ro, hp, mn)) => (ro, hp, mn),\n None => {\n error!(\"Cipher ownership assertion failure\");\n (true, true, false)\n }\n }\n} else {\n (false, false, false)\n};\n```\nsrc/db/models/cipher.rs:335\n\n```rust\nlet mut json_object = json!({\n \"object\": \"cipherDetails\",\n \"id\": self.uuid,\n \"type\": self.atype,\n ...\n \"name\": self.name,\n \"notes\": self.notes,\n \"fields\": fields_json,\n \"data\": data_json,\n ...\n});\n```\n\n\n## Preconditions\n\n* The attacker possesses a valid regular-user JWT (Bearer token).\n* The attacker knows the target (victim) `cipher_id`.\n\n\n## Steps to Reproduce\n\n1. Prepare the attacker JWT and victim `cipher_id` (preconditions).\n2. Baseline check: confirm that standard retrieval is denied.\n![\"image\"](\"https://github.com/user-attachments/assets/32b12cc9-3672-4a88-afd0-ef7715474662\")
\n\n\n3. Execute the vulnerable API. Confirm that **200 OK** is returned and that `cipherDetails` includes fields such as `id`, `name`, `notes`, `secureNote`, etc.\n![\"image\"](\"https://github.com/user-attachments/assets/341b330c-8d55-4f06-a622-0d7da28f62fd\")
\n\n\n## Potential Impact\n\n* Unauthorized disclosure of other users’ cipher information (confidentiality breach).\n* Creation of unauthorized associations within the attacker’s user context (e.g., `favorite` or folder operations).\n* The response from `/api/ciphers//partial` includes `attachments[].url`.\n\nIn filesystem (FS) deployments, this returns a tokenized endpoint such as:\n\n```\n/attachments//?token=...\n```\n\nIn object storage deployments, it returns a short-lived pre-signed URL.\n\nAs a result, an attacker can use these URLs to directly download attachment data that they are not authorized to access.\n\nThis can lead to disclosure of sensitive information stored in the Vault, including personal data and authentication credentials. Such exposure may further result in account compromise, lateral movement, and other secondary impacts.",
"title": "github - https://github.com/advisories/GHSA-w9f8-m526-h7fh"
},
{
"category": "description",
"text": "Vaultwarden is an unofficial Bitwarden compatible server written in Rust, formerly known as bitwarden_rs. Prior to version 1.35.4, an authenticated regular user can specify another user’s cipher_id and call \"PUT /api/ciphers/{id}/partial\" Even though the standard retrieval API correctly denies access to that cipher, the partial update endpoint returns 200 OK and exposes cipherDetails (including name, notes, data, secureNote, etc.). This issue has been patched in version 1.35.4.",
"title": "nvd - https://nvd.nist.gov/vuln/detail/CVE-2026-27898"
},
{
"category": "description",
"text": "Vaultwarden is an unofficial Bitwarden compatible server written in Rust, formerly known as bitwarden_rs. Prior to version 1.35.4, an authenticated regular user can specify another user’s cipher_id and call \"PUT /api/ciphers/{id}/partial\" Even though the standard retrieval API correctly denies access to that cipher, the partial update endpoint returns 200 OK and exposes cipherDetails (including name, notes, data, secureNote, etc.). This issue has been patched in version 1.35.4.",
"title": "cveprojectv5 - https://www.cve.org/CVERecord?id=CVE-2026-27898"
},
{
"category": "description",
"text": "No description is available for this CVE.\nThis MODERATE information disclosure vulnerability in Vaultwarden allows an authenticated user to retrieve another user's cipher details via the partial update API endpoint (CWE-639 IDOR). Exploitation requires network access and valid authentication (PR:L). Impact is limited to high confidentiality loss (exposure of names, notes, secure notes); no integrity or availability impact. Affects versions prior to 1.35.4. Red Hat does not ship Vaultwarden.",
"title": "redhat - https://access.redhat.com/security/cve/CVE-2026-27898"
},
{
"category": "other",
"text": "0.0003",
"title": "EPSS"
},
{
"category": "other",
"text": "4.5",
"title": "NCSC Score"
},
{
"category": "other",
"text": "There is product data available from source Certbundde",
"title": "NCSC Score top increasing factors"
},
{
"category": "other",
"text": "The value of the most recent EPSS score, Is related to (a version of) an uncommon product, Is related to a product by vendor Open Source",
"title": "NCSC Score top decreasing factors"
},
{
"category": "details",
"text": "Severity: 2\n",
"title": "Vendor assessment"
}
],
"product_status": {
"known_affected": [
"CSAFPID-5759412",
"CSAFPID-5761788",
"CSAFPID-5761789"
]
},
"references": [
{
"category": "external",
"summary": "Source - github",
"url": "https://github.com/advisories/GHSA-w9f8-m526-h7fh"
},
{
"category": "external",
"summary": "Source raw - github",
"url": "https://api.github.com/advisories/GHSA-w9f8-m526-h7fh"
},
{
"category": "external",
"summary": "Source - nvd",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-27898"
},
{
"category": "external",
"summary": "Source raw - nvd",
"url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-27898"
},
{
"category": "external",
"summary": "Source - cveprojectv5",
"url": "https://www.cve.org/CVERecord?id=CVE-2026-27898"
},
{
"category": "external",
"summary": "Source raw - cveprojectv5",
"url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/27xxx/CVE-2026-27898.json"
},
{
"category": "external",
"summary": "Source - certbundde",
"url": "https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-0594.json"
},
{
"category": "external",
"summary": "Source - redhat",
"url": "https://access.redhat.com/security/cve/CVE-2026-27898"
},
{
"category": "external",
"summary": "Source raw - redhat",
"url": "https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-27898.json"
},
{
"category": "external",
"summary": "Source - first",
"url": "https://api.first.org/data/v1/epss?cve=CVE-2026-27898"
},
{
"category": "external",
"summary": "Source raw - first",
"url": "https://api.first.org/data/v1/epss?limit=10000&offset=0"
},
{
"category": "external",
"summary": "Source - first",
"url": "https://api.first.org/data/v1/epss?limit=10000&offset=0"
},
{
"category": "external",
"summary": "Reference - cveprojectv5; github; nvd; redhat",
"url": "https://github.com/dani-garcia/vaultwarden/security/advisories/GHSA-w9f8-m526-h7fh"
},
{
"category": "external",
"summary": "Reference - certbundde; github",
"url": "https://github.com/advisories/GHSA-w9f8-m526-h7fh"
},
{
"category": "external",
"summary": "Reference - certbundde",
"url": "https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-0594.json"
},
{
"category": "external",
"summary": "Reference - certbundde",
"url": "https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-0594"
},
{
"category": "external",
"summary": "Reference - certbundde",
"url": "https://github.com/advisories/GHSA-h4hq-rgvh-wh27"
},
{
"category": "external",
"summary": "Reference - certbundde",
"url": "https://github.com/advisories/GHSA-r32r-j5jq-3w4m"
},
{
"category": "external",
"summary": "Reference - certbundde",
"url": "https://github.com/advisories/GHSA-v6pg-v89r-w8wr"
},
{
"category": "external",
"summary": "Reference - redhat",
"url": "https://www.cve.org/CVERecord?id=CVE-2026-27898"
},
{
"category": "external",
"summary": "Reference - redhat",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-27898"
}
],
"scores": [
{
"cvss_v3": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
"baseScore": 6.5,
"baseSeverity": "MEDIUM"
},
"products": [
"CSAFPID-5759412",
"CSAFPID-5761788",
"CSAFPID-5761789"
]
}
],
"title": "CVE-2026-27898"
}
]
}