CVE-2026-41262 — v4
MEDIUMCVE-2026-41262 is a medium-severity (CVSS 4.3) CWE-863 vulnerability in github.com/fleetdm/fleet/v4. A fix is available for github.com/fleetdm/fleet/v4 — see the affected versions and patch details below.
Fleet: Cross-Team Policy Data Exposure via Global Policy Read Endpoint
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-41262.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-41262 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 376,715 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/fleetdm/fleet/v4Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
Fleet is an open-source device management platform built on osquery. In versions prior to 4.85.0, the global policy read endpoint (GET /api/latest/fleet/policies/{policy_id}) fails to verify team ownership of the requested policy, allowing an authenticated user with observer-level access on any single team to read the full details of policies belonging to any other team and bypass Fleet's team isolation model. The handler authorizes the request against an empty policy object whose TeamID is nil, which an authorization rule permits for any user holding a role on any team, and then fetches the policy by ID with no team filter and returns it without any post-fetch scope check. Because policy IDs are sequential integers, an attacker can enumerate them to read other teams' policy SQL queries, host pass and fail counts, and associated software-installer and script metadata, exposing security-monitoring strategies and compliance posture across team boundaries. This issue is fixed in version 4.85.0.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/fleetdm/fleet/v4 | all versions | 4.85.0go get github.com/fleetdm/fleet/v4@v4.85.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/fleetdm/fleet/v4, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/fleetdm/fleet/v4 to 4.85.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-41262 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-41262 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-41262. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-41262 in your dependencies?
O3 Security finds CVE-2026-41262 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.