Fleet
CVE-2020-26276
CRITICAL
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A07:2025 - Authentication Failures
ASVS 5.0
V6 - Authentication Anti-spoofing controls
MITRE ATT&CK
1 technique across 1 tactic: Defense Evasion The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 9.8 (CRITICAL). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. |
| Exploit ScenarioDerived | This vulnerability can be exploited remotely over the network. Successful exploitation could compromise the critical-severity affected system. |
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Alert meAnalysisAI
Fleet is an open source osquery manager. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in go
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified under CWE-290. Fleet is an open source osquery manager. In Fleet before version 3.5.1, due to issues in Go's standard library XML parsing, a valid SAML response may be mutated by an attacker to modify the trusted document. This can result in allowing unverified logins from a SAML IdP. Users that configure Fleet with SSO login may be vulnerable to this issue. This issue is patched in 3.5.1. The fix was made using https://github.com/mattermost/xml-roundtrip-validator If upgrade to 3.5.1 is not possible, users should disable SSO authentication in Fleet. Affected products include: Fleetdm Fleet. Version information: version 3.5.1.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
Fleet is an open source osquery manager. In Fleet before version 3.5.1, due to issues in Go's standard library XML parsing, a valid SAML response may be mutated by an attacker to modify the trusted document. This can result in allowing unverified logins from a SAML IdP. Users that configure Fleet with SSO login may be vulnerable to this issue. This issue is patched in 3.5.1. The fix was made using https://github.com/mattermost/xml-roundtrip-validator If upgrade to 3.5.1 is not possible, users should disable SSO authentication in Fleet.
Threat Intelligence Overview
NVD
CVE.org
EPSS
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.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.
Affected Products (CPE)NVD
Fleet device management software has a signature verification bypass that allows attackers to install malicious firmware
Unauthenticated attackers can bypass authentication in Fleet (versions before 4.87.0) by using non-secret device identif
OS command injection in Fleet's generator for Fleet-maintained macOS app install and uninstall scripts allows crafted Ho
Privilege escalation in SUSE Rancher Fleet (0.14.x before 0.14.11, 0.15.x before 0.15.7, and 0.16.x before 0.16.2) lets
SQL injection in Fleet device management software before version 4.80.1 allows authenticated users to manipulate the ord
Unauthenticated denial of service in FleetDM Fleet before 4.83.0 allows remote attackers to exhaust server memory by sen
Unauthenticated denial-of-service in Fleet Device Management before 4.89.0 allows remote attackers to crash the server b
Fleet device management software versions prior to 4.78.3 suffer from broken access control that permits any authenticat
fleetdm/fleet is an open source device management, built on osquery. Rated high severity (CVSS 8.1), this vulnerability
Fleet before 2.1.2 allows exposure of SMTP credentials. Rated high severity (CVSS 7.5), this vulnerability is remotely e
Cross-tenant authorization bypass in SUSE Rancher Fleet allows a party who can perform agent-initiated cluster registrat
Unauthenticated download of in-house iOS application packages and manifests is possible against enterprise-tier Fleet de
Exploit-DB