What is the CVSS score of CVE-2026-27803?

CVE-2026-27803 has a CVSS 3.1 base score of 8.3 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L. EPSS exploitation probability: 0.0%.

How to fix or mitigate CVE-2026-27803?

Within 24 hours: Identify all Vaultwarden deployments and document current versions; review audit logs for unauthorized manager activity on collections with manage=false permissions. Within 7 days: Implement network segmentation to restrict Vaultwarden access to essential users only; enforce multi-factor authentication for all manager accounts. Within 30 days: Deploy Vaultwarden 1.35.4 or later when available; conduct full access control audit of all collection permissions and remediate any unauthorized changes.

Vaultwarden CVE-2026-27803

HIGH

Improper Privilege Management (CWE-269)

2026-03-04 security-advisories@github.com

GHSA-h4hq-rgvh-wh27

Privilege Escalation Red Hat Vaultwarden Dani Garcia

8.3

CVSS 3.1 · GitHub Advisory

View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

Access

Authenticate as Manager with collection access
Exploit

Bypass manage=false restriction
Execution

Perform unauthorized collection management
Impact

Modify or exfiltrate sensitive vault data

Vulnerability Assessment

Weakness	CWE CWE-269 OWASP Top 10:2025 A06:2025 - Insecure Design ASVS 5.0 V8 - Authorization Least privilege enforcement MITRE ATT&CK 1 technique across 1 tactic: Privilege Escalation The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. Sign in to read
Exploitation Conditions	User must have Manager role with PR:L (low privilege) access to at least one collection in Vaultwarden versions before 1.35.4, where manage=false permission flag is improperly enforced for collection operations.
Impact	CVSS 8.3 (HIGH). Attack vector: Network. Complexity: Low. Privileges required: Low. User interaction: None.
Exploit ScenarioDerived	An attacker could exploit this vulnerability to compromise the affected system.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).

Patch available 0.0% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 12, 2026

Vaultwarden versions prior to 1.35.4 fail to properly enforce collection management permissions, allowing authenticated users with Manager roles to perform restricted management operations on collections where they lack authorization. An attacker with valid credentials can exploit this privilege escalation to modify or control collections they should not have access to. No patch is currently available for affected deployments.

Earlier versions of this analysis (1)

v1 Mar 12, 2026 - 22:05 CVSS 8.3

Vaultwarden is an unofficial Bitwarden compatible server written in Rust, formerly known as bitwarden_rs. Prior to version 1.35.4, when a Manager has manage=false for a given collection, they can still perform several management operations as long as they have access to the collection. [CVSS 8.3 HIGH]

RemediationAI

Fixed in version 1.35.4.. Restrict network access to the affected service where possible.

Affected Packages

cargo vaultwarden fix: 1.35.4

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in cargo

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

Classified as CWE-269 (Improper Privilege Management). Affects Vaultwarden. Vaultwarden is an unofficial Bitwarden compatible server written in Rust, formerly known as bitwarden_rs. Prior to version 1.35.4, when a Manager has manage=false for a given collection, they can still perform several management operations as long as they have access to the collection. This issue has been patched in version 1.35.4.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

GitHub Advisory PRIMARY 8.3 HIGH

AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L

Red Hat 8.3 HIGH

Primary rating from GitHub Advisory.

CVSS VectorGitHub Advisory

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

Low

Lifecycle Timeline

Patch released

Mar 31, 2026 - 21:13 nvd

Patch available

CVE Published

Mar 04, 2026 - 22:16 nvd

HIGH 8.3

DescriptionGitHub Advisory

Executive ViewAI

Why It Matters

Vaultwarden instances running versions prior to 1.35.4 contain an access control bypass vulnerability allowing managers with restricted permissions to perform unauthorized collection management operations. Organizations using Vaultwarden for credential management face elevated risk of unauthorized access to sensitive vault data and potential lateral movement through compromised credentials.

Business Impact: High

Compensating Controls

Immediately restrict manager role assignments to only trusted personnel with documented justification; implement role-based access control review process with approval workflow for collection permissions; enable comprehensive audit logging and monitoring for collection modification events; consider network segmentation to limit manager access scope; evaluate temporary credential rotation for all accounts with manager privileges until patch is applied.

Threat Intelligence Overview

EPSS Score

0.0%

Top 86% exploitable

Data Quality

4 sources

Confidence: Medium

NVD

CVE.org

EPSS Vendor

GitHub

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity HIGH

CISA KEV No

Public POC No

EPSS 0.0%

Patch available Yes

Active threat No

Deciding rule

HIGH severity (CVSS 7.0-8.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Scheduled

Exploitation· derived

None

System Exposure· derived

Open

Automatable· derived

Human Impact

High

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +42

PoC: 0

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Privilege Escalation HIGH

Privilege escalation occurs when an attacker leverages flaws in access control mechanisms to gain permissions beyond what they were originally granted.