CVE-2026-22808: GO-2026-4336 - Fleet Windows MDM endpoint has a Cross-site Scripting vulnerability in github.com/fleetdm/fleet

Quick answers

Is CVE-2026-22808 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-22808 being exploited in the wild.

How severe is CVE-2026-22808?

Medium severity, with a CVSS score of 4, published 3 February 2026.

Which products and versions are affected?

github.com/fleetdm/fleet (Go) SEMVER:introduced=4.78.0,fixed=4.78.2; github.com/fleetdm/fleet/v4 (Go) SEMVER:introduced=0,fixed=4.43.5-0.20260111020427-0e6c790803d1, SEMVER:introduced=4.75.0,fixed=4.75.2,introduced=4.76.0,fixed=4.76.2,introduced=4.77.0,fixed=4.77.1,introduced=4.78.0,fixed=4.78.2.

Is there a fix for CVE-2026-22808?

Yes. github.com/fleetdm/fleet (Go): upgrade to 4.78.2 or later; github.com/fleetdm/fleet/v4 (Go): upgrade to 4.43.5-0.20260111020427-0e6c790803d1, 4.78.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Am I affected by CVE-2026-22808?

Check whether you run github.com/fleetdm/fleet (Go) or github.com/fleetdm/fleet/v4 (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

• github.com/fleetdm/fleet (Go): upgrade to 4.78.2 or later

  go get github.com/fleetdm/fleet@v4.78.2

• github.com/fleetdm/fleet/v4 (Go): upgrade to 4.43.5-0.20260111020427-0e6c790803d1, 4.78.2 or later

  go get github.com/fleetdm/fleet/v4@v4.78.2

Affected products

• github.com/fleetdm/fleet (Go) SEMVER:introduced=4.78.0,fixed=4.78.2
• github.com/fleetdm/fleet/v4 (Go) SEMVER:introduced=0,fixed=4.43.5-0.20260111020427-0e6c790803d1, SEMVER:introduced=4.75.0,fixed=4.75.2,introduced=4.76.0,fixed=4.76.2,introduced=4.77.0,fixed=4.77.1,introduced=4.78.0,fixed=4.78.2

Identifiers

• CVE-2026-22808
• GHSA-gfpw-jgvr-cw4j
• GO-2026-4336