# CVE-2026-27802: vaultwarden — Fixed in 1.35.4 🦀 🦀 crates.io Not in CISA KEV HIGH severity # CVE-2026-27802 — vaultwarden HIGH CVE-2026-27802 is a high-severity (CVSS 8.3) Improper Privilege Management vulnerability in vaultwarden. A fix is available for vaultwarden — see the affected versions and patch details below. Vaultwarden: Privilege Escalation via Bulk Permission Update to Unauthorized Collections by Manager Also known as[GHSA-r32r-j5jq-3w4m](/vulnerability/GHSA-r32r-j5jq-3w4m) Published Mar 4, 2026 Updated Oct 28, 2026 Affected 1 pkg Patched 1 / 1 Exploits None indexed Exploitation data as of Nov 5, 2026 · OSV.dev, NVD, FIRST.org (EPSS) ## Exploitation Status ### No confirmed exploitation observed yet - A successful exploit gives an attacker total control of the affected component, not partial access. - CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment. Exploitation and automatability from CISA’s SSVC triage for CVE-2026-27802. ## EPSS Exploitation Probability [via FIRST.org ↗](https://www.first.org/epss/) 0.3%probability of exploitation in next 30 days Lower Risk\-0.04% Lower risk than most CVEs27th percentile — riskier than 27% of all scored CVEsHighest risk 0.00%0.29%0.58%0.87%0.1%0.3%May 26Sep 26Nov 26 Probability of exploitation in the next 30 days, from [FIRST.org EPSS](https://www.first.org/epss/). ## How urgent is this, really ## Where this sits among everything scored ## Real-World Exposure 1 pkg affected 🦀`vaultwarden` Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems. ## Description ### Summary A 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. The API allowed changing `assigned=false` to `assigned=true`, resulting in unauthorized access. Additionally, 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. * * * ### Description - The endpoint accepts `ManagerHeadersLoose` and does not validate access rights for the specified `collectionIds`. src/api/core/organizations.rs:551 ``` headers: ManagerHeadersLoose, ``` - The received `collection_ids` are processed directly without per-collection authorization checks. src/api/core/organizations.rs:564 ``` for col_id in data.collection_ids { ``` - Existing group assignments for the collection are deleted. src/api/core/organizations.rs:583 ``` CollectionGroup::delete_all_by_collection(&col_id, &conn).await?; ``` - Existing user assignments for the collection are deleted. src/api/core/organizations.rs:590 ``` CollectionUser::delete_all_by_collection(&col_id, &conn).await?; ``` - By comparison, another bulk-processing endpoint performs per-collection validation using `from_loose`. src/api/core/organizations.rs:787 ``` let headers = ManagerHeaders::from_loose(headers, &collections, &conn).await?; ``` - The actual access control logic is implemented in `can_access_collection`, which is not invoked in the bulk-access endpoint. src/auth.rs:911 ``` if !Collection::can_access_collection(&h.membership, col_id, conn).await { ``` * * * ### Preconditions - The attacker possesses a valid **Manager account** within the target organization. - The organization contains collections that are **not assigned** to the attacker. - The attacker can authenticate through the standard API login process (Owner/Admin privileges are not required). * * * ### Steps to Reproduce 1. Log in as a Manager and obtain a Bearer token. image 2. Confirm the current values of `assigned`, `manage`, `readOnly`, and `hidePasswords` for the target collection. image 3. Verify that the standard update API returns **401 Unauthorized** when attempting to modify the unassigned collection. image 4. Invoke the bulk-access API, including: image - `collectionIds` containing the target collection - `users` containing the attacker’s own `membership_id` Confirm that the API returns **200 OK**. 5. Re-run the standard update API. Confirm that it now succeeds and that the previously unauthorized modification is applied. image * * * ### Required Minimum Privileges - Manager role within the target organization (the issue occurs even when `access_all=false`) * * * ### Attack Scenario A 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. Because 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. * * * ### Potential Impact - **Confidentiality:** Unauthorized access to sensitive information within restricted collections. - **Integrity:** Unauthorized modification of collection permission settings and arbitrary changes to access controls. - **Availability:** Deletion of existing assignments may cause legitimate users to lose access. ## Affected Packages 1 total 1 fixed Ecosystem Package Vulnerable range Fix 🦀crates.io `vaultwarden` all versions 1.35.4`cargo update -p vaultwarden --precise 1.35.4` ## Affected Products 1 product · 1 configurations Application `vaultwarden`dani-garcia < 1.35.4 range ## Detection & mitigation playbook Open-source dependency 1. ### Detect Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for vaultwarden, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version. 2. ### Fix Update vaultwarden to 1.35.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-27802 is resolved across your whole dependency graph. 3. ### Workarounds Close the privilege gap rather than the entry point: audit which accounts, roles and service identities can reach the affected operation, drop the component to the least privilege it actually needs, and review file and directory permissions created by earlier installs — a default left in place is what makes this reachable. ## Frequently Asked Questions \## Summary A 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. The API allowed changing \`assigned=false\` to \`assigned=true\`, resulting in unauthorized access. Additionally, 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. --- ## Description \* The endpoint accept O3 Security · Impact-Aware SCA ### Is CVE-2026-27802 in your dependencies? Find it across crates.io, including transitive dependencies. [Scan my dependencies](/book-demo) [How O3 SCA works](/impact-aware-sca)