# 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. - **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 6 Mar 2025 - **Updated:** 6 Mar 2025 - **Also known as:** GHSA-52jx-g6m5-h735, GO-2025-3505 ## 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 (Improper Authorization) ## Which versions are affected by CVE-2025-27509? 11 open source packages ship an affected version, including github.com/fleetdm/fleet/v4. | Package | Ecosystem | 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 | | `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. ## 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: - https://github.com/Chillov3k/poc-cve-2025-27509 (github_poc): https://github.com/Chillov3k/poc-cve-2025-27509 ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2025-27509 and fix it if it is affected. What it is: 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. Exploitation: There is no known exploitation of CVE-2025-27509 in the wild and no public exploit code. Affected packages and fixed versions: - github.com/fleetdm/fleet/v4 (Go): affected all versions; no fix listed - github.com/fleetdm/fleet/v4 (Go): affected all versions; fixed in 4.53.2 - github.com/fleetdm/fleet/v4 (Go): affected all versions; fixed in 4.53.2 - github.com/fleetdm/fleet/v4 (Go): affected from 4.54.0; fixed in 4.58.1 - github.com/fleetdm/fleet/v4 (Go): affected from 4.54.0; fixed in 4.58.1 - github.com/fleetdm/fleet/v4 (Go): affected from 4.62.0; fixed in 4.62.4 - github.com/fleetdm/fleet/v4 (Go): affected from 4.62.0; fixed in 4.62.4 - github.com/fleetdm/fleet/v4 (Go): affected from 4.63.0; fixed in 4.63.2 - github.com/fleetdm/fleet/v4 (Go): affected from 4.63.0; fixed in 4.63.2 - github.com/fleetdm/fleet/v4 (Go): affected from 4.64.0; fixed in 4.64.2 - github.com/fleetdm/fleet/v4 (Go): affected from 4.64.0; fixed in 4.64.2 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2025-27509/ (Markdown: https://insights.sbomify.com/CVE-2025-27509/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2025-27509 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-27509 - OSV: https://osv.dev/vulnerability/CVE-2025-27509 --- From sbomify Insights: https://insights.sbomify.com/CVE-2025-27509/ Summaries are generated and may contain mistakes; the official description above is the record.