CVSS 3.1
9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HCVE-2020-26276
Critical (9.8) in fleetdm fleet. EPSS 2.2% chance of exploitation in the next 30 days. Fixed in github.com/fleetdm/fleet/v4 3.5.1.
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.
Severity
- EPSS
- 2.2% chance of exploitation in the next 30 days; higher than 82% of CVEs (scores of 2026-10-31)
- CWE
- CWE-290
- Published
- Modified
- Record from
- the NVD, synced
Affected
- fleetdm:fleet
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-w3wf-cfx3-6gcx | Go | github.com/fleetdm/fleet/v4 | <3.5.1 | 3.5.1 |
References
- https://github.com/fleetdm/fleet/blob/master/CHANGELOG.md#fleet-351-dec-14-2020
- https://github.com/fleetdm/fleet/commit/57812a532e5f749c8e18c6f6a652eca65c083607
- https://github.com/fleetdm/fleet/security/advisories/GHSA-w3wf-cfx3-6gcx
- https://github.com/mattermost/xml-roundtrip-validator
- https://mattermost.com/blog/coordinated-disclosure-go-xml-vulnerabilities