{
"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-2026-27802",
"tracking": {
"current_release_date": "2026-03-23T03:00:51.711230Z",
"generator": {
"date": "2026-02-17T15:00:00Z",
"engine": {
"name": "V.E.L.M.A",
"version": "1.7"
}
},
"id": "CVE-2026-27802",
"initial_release_date": "2026-03-04T20:39:48.062995Z",
"revision_history": [
{
"date": "2026-03-04T20:39:48.062995Z",
"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": "2026-03-04T22:25:29.761698Z",
"number": "3",
"summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (1).| CWES updated (1)."
},
{
"date": "2026-03-04T22:25:32.887070Z",
"number": "4",
"summary": "NCSC Score updated."
},
{
"date": "2026-03-04T22:39:53.017859Z",
"number": "5",
"summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products created (1).| References created (1).| CWES updated (1)."
},
{
"date": "2026-03-04T22:39:54.784534Z",
"number": "6",
"summary": "NCSC Score updated."
},
{
"date": "2026-03-05T11:06:15.794233Z",
"number": "7",
"summary": "Source connected.| CVE status created. (valid)| Products created (1).| Products connected (1).| References created (6)."
},
{
"date": "2026-03-05T11:06:17.764389Z",
"number": "8",
"summary": "NCSC Score updated."
},
{
"date": "2026-03-05T12:30:37.212862Z",
"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": "2026-03-05T12:30:39.428322Z",
"number": "10",
"summary": "NCSC Score updated."
},
{
"date": "2026-03-05T14:14:09.203538Z",
"number": "11",
"summary": "Source created.| CVE status created. (valid)| EPSS created."
},
{
"date": "2026-03-05T14:14:15.149106Z",
"number": "12",
"summary": "NCSC Score updated."
},
{
"date": "2026-03-05T16:39:46.562859Z",
"number": "13",
"summary": "Unknown change."
},
{
"date": "2026-03-06T20:26:20.425752Z",
"number": "14",
"summary": "Products connected (1).| Product Identifiers created (1)."
},
{
"date": "2026-03-06T20:26:24.471617Z",
"number": "15",
"summary": "NCSC Score updated."
},
{
"date": "2026-03-11T15:58:19.839806Z",
"number": "16",
"summary": "NCSC Score updated."
},
{
"date": "2026-03-20T09:39:45.531400Z",
"number": "17",
"summary": "Source connected.| CVE status created. (valid)| EPSS created."
},
{
"date": "2026-03-20T09:39:48.606180Z",
"number": "18",
"summary": "NCSC Score updated."
}
],
"status": "interim",
"version": "18"
}
},
"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-2026-27802",
"cwe": {
"id": "CWE-863",
"name": "Incorrect Authorization"
},
"notes": [
{
"category": "description",
"text": "## Summary\n\nA Manager account (`access_all=false`) was able to escalate privileges by directly invoking the **bulk-access API** against collections that were not originally assigned to them.\nThe API allowed changing `assigned=false` to `assigned=true`, resulting in unauthorized access.\n\nAdditionally, prior to the bulk-access call, the regular single-update API correctly returned **401 Unauthorized** for the same collection. After executing the bulk-access API, the same update API returned **200 OK**, confirming an authorization gap at the HTTP level.\n\n---\n\n## Description\n\n* The endpoint accepts `ManagerHeadersLoose` and does not validate access rights for the specified `collectionIds`.\n src/api/core/organizations.rs:551\n\n ```rust\n headers: ManagerHeadersLoose,\n ```\n\n* The received `collection_ids` are processed directly without per-collection authorization checks.\n src/api/core/organizations.rs:564\n\n ```rust\n for col_id in data.collection_ids {\n ```\n\n* Existing group assignments for the collection are deleted.\n src/api/core/organizations.rs:583\n\n ```rust\n CollectionGroup::delete_all_by_collection(&col_id, &conn).await?;\n ```\n\n* Existing user assignments for the collection are deleted.\n src/api/core/organizations.rs:590\n\n ```rust\n CollectionUser::delete_all_by_collection(&col_id, &conn).await?;\n ```\n\n* By comparison, another bulk-processing endpoint performs per-collection validation using `from_loose`.\n src/api/core/organizations.rs:787\n\n ```rust\n let headers = ManagerHeaders::from_loose(headers, &collections, &conn).await?;\n ```\n\n* The actual access control logic is implemented in `can_access_collection`, which is not invoked in the bulk-access endpoint.\n src/auth.rs:911\n\n ```rust\n if !Collection::can_access_collection(&h.membership, col_id, conn).await {\n ```\n\n---\n\n## Preconditions\n\n* The attacker possesses a valid **Manager account** within the target organization.\n* The organization contains collections that are **not assigned** to the attacker.\n* The attacker can authenticate through the standard API login process (Owner/Admin privileges are not required).\n\n---\n\n## Steps to Reproduce\n\n1. Log in as a Manager and obtain a Bearer token.\n![\"image\"](\"https://github.com/user-attachments/assets/218f05e2-6a2e-4066-8f8d-6bbef1cc5858\")
\n\n2. Confirm the current values of `assigned`, `manage`, `readOnly`, and `hidePasswords` for the target collection.\n![\"image\"](\"https://github.com/user-attachments/assets/a6d2fc70-5370-4984-85bd-a6f74febdfa3\")
\n\n3. Verify that the standard update API returns **401 Unauthorized** when attempting to modify the unassigned collection.\n![\"image\"](\"https://github.com/user-attachments/assets/802f0d2b-d474-44d2-beef-b4f7f3335225\")
\n\n4. Invoke the bulk-access API, including:\n![\"image\"](\"https://github.com/user-attachments/assets/1d3caa01-3ac2-4636-9ed0-189e5923c986\")
\n\n * `collectionIds` containing the target collection\n * `users` containing the attacker’s own `membership_id`\n Confirm that the API returns **200 OK**.\n\n5. Re-run the standard update API.\n Confirm that it now succeeds and that the previously unauthorized modification is applied.\n![\"image\"](\"https://github.com/user-attachments/assets/340e9676-d802-404c-b894-9986a176360a\")
\n\n---\n\n## Required Minimum Privileges\n\n* Manager role within the target organization\n (the issue occurs even when `access_all=false`)\n\n---\n\n## Attack Scenario\n\nA delegated administrator or department-level Manager within an organization directly calls the API to add themselves to unauthorized collections and gain access to confidential information.\n\nBecause the bulk update process deletes and reassigns existing permissions, the attacker can also remove other users’ access, enabling denial-of-service or sabotage within the organization.\n\n---\n\n## Potential Impact\n\n* **Confidentiality:** Unauthorized access to sensitive information within restricted collections.\n* **Integrity:** Unauthorized modification of collection permission settings and arbitrary changes to access controls.\n* **Availability:** Deletion of existing assignments may cause legitimate users to lose access.",
"title": "github - https://github.com/advisories/GHSA-r32r-j5jq-3w4m"
},
{
"category": "description",
"text": "Vaultwarden is an unofficial Bitwarden compatible server written in Rust, formerly known as bitwarden_rs. Prior to version 1.35.4, there is a privilege escalation vulnerability via bulk permission update to unauthorized collections by Manager. This issue has been patched in version 1.35.4.",
"title": "cveprojectv5 - https://www.cve.org/CVERecord?id=CVE-2026-27802"
},
{
"category": "description",
"text": "Vaultwarden is an unofficial Bitwarden compatible server written in Rust, formerly known as bitwarden_rs. Prior to version 1.35.4, there is a privilege escalation vulnerability via bulk permission update to unauthorized collections by Manager. This issue has been patched in version 1.35.4.",
"title": "nvd - https://nvd.nist.gov/vuln/detail/CVE-2026-27802"
},
{
"category": "description",
"text": "No description is available for this CVE.\nThis IMPORTANT privilege escalation vulnerability in Vaultwarden allows a Manager to update permissions for unauthorized collections via the bulk update functionality. Exploitation requires network access and a Manager-level account (PR:L). Impact includes high confidentiality loss (access to restricted collections) and high integrity loss (permission modification). Affects versions prior to 1.35.4. Red Hat does not ship Vaultwarden.",
"title": "redhat - https://access.redhat.com/security/cve/CVE-2026-27802"
},
{
"category": "other",
"text": "0.00045",
"title": "EPSS"
},
{
"category": "other",
"text": "4.8",
"title": "NCSC Score"
},
{
"category": "other",
"text": "There is product data available from source Certbundde, There is product data available from source Nvd",
"title": "NCSC Score top increasing factors"
},
{
"category": "other",
"text": "The CVSS vector string contains A:H (Availability Impact: High), There is cwe data available from source Github, 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: 3\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-r32r-j5jq-3w4m"
},
{
"category": "external",
"summary": "Source raw - github",
"url": "https://api.github.com/advisories/GHSA-r32r-j5jq-3w4m"
},
{
"category": "external",
"summary": "Source - nvd",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-27802"
},
{
"category": "external",
"summary": "Source raw - nvd",
"url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-27802"
},
{
"category": "external",
"summary": "Source - cveprojectv5",
"url": "https://www.cve.org/CVERecord?id=CVE-2026-27802"
},
{
"category": "external",
"summary": "Source raw - cveprojectv5",
"url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/27xxx/CVE-2026-27802.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-2026-27802"
},
{
"category": "external",
"summary": "Source raw - redhat",
"url": "https://access.redhat.com/hydra/rest/securitydata/cve/CVE-2026-27802.json"
},
{
"category": "external",
"summary": "Source - first",
"url": "https://api.first.org/data/v1/epss?cve=CVE-2026-27802"
},
{
"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-r32r-j5jq-3w4m"
},
{
"category": "external",
"summary": "Reference - certbundde; github",
"url": "https://github.com/advisories/GHSA-r32r-j5jq-3w4m"
},
{
"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-v6pg-v89r-w8wr"
},
{
"category": "external",
"summary": "Reference - certbundde",
"url": "https://github.com/advisories/GHSA-w9f8-m526-h7fh"
},
{
"category": "external",
"summary": "Reference - redhat",
"url": "https://www.cve.org/CVERecord?id=CVE-2026-27802"
},
{
"category": "external",
"summary": "Reference - redhat",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-27802"
}
],
"scores": [
{
"cvss_v3": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L",
"baseScore": 8.3,
"baseSeverity": "HIGH"
},
"products": [
"CSAFPID-5759412",
"CSAFPID-5761788",
"CSAFPID-5761789"
]
}
],
"title": "CVE-2026-27802"
}
]
}