CVE-2025-27509 SAML authentication vulnerability due to improper SAML response validation
Attackers can forge SAML responses to bypass authentication and create administrative accounts if JIT provisioning or MDM enrollment is enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-27509?
CVE-2025-27509 is a critical authentication bypass vulnerability in fleetdm fleet, published on 6 Mar 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
fleetdm/fleet is an open source device management, built on osquery. In vulnerable versions of Fleet, an attacker could craft a specially-formed SAML response to forge authentication assertions, provision a new administrative user account if Just-In-Time (JIT) provisioning is enabled, or create new accounts tied to forged assertions if f MDM enrollment is enabled. This vulnerability is fixed in 4.64.2, 4.63.2, 4.62.4, and 4.58.1.
Weakness: CWE-285
Which versions are affected by CVE-2025-27509?
11 open source packages ship an affected version, including github.com/fleetdm/fleet/v4.
| Package | Affected | Fixed in |
|---|---|---|
github.com/fleetdm/fleet/v4 Go | All versions | None |
github.com/fleetdm/fleet/v4 Go | All versions | 4.53.2 |
github.com/fleetdm/fleet/v4 Go | All versions | 4.53.2 |
github.com/fleetdm/fleet/v4 Go | From 4.54.0 | 4.58.1 |
github.com/fleetdm/fleet/v4 Go | From 4.54.0 | 4.58.1 |
github.com/fleetdm/fleet/v4 Go | From 4.62.0 | 4.62.4 |
5 more packages
github.com/fleetdm/fleet/v4 Go | From 4.62.0 | 4.62.4 |
github.com/fleetdm/fleet/v4 Go | From 4.63.0 | 4.63.2 |
github.com/fleetdm/fleet/v4 Go | From 4.63.0 | 4.63.2 |
github.com/fleetdm/fleet/v4 Go | From 4.64.0 | 4.64.2 |
github.com/fleetdm/fleet/v4 Go | From 4.64.0 | 4.64.2 |
How do I fix CVE-2025-27509?
Upgrade github.com/fleetdm/fleet/v4 to a fixed version for your release line: 4.53.2, 4.58.1, 4.62.4 or 4.63.2.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2025-27509 being exploited?
There is no known exploitation of CVE-2025-27509 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as GHSA-52jx-g6m5-h735, GO-2025-3505.