CVE-2026-22808

MEDIUMCVSS 5.5/10EPSS 0.21%

Last modified

CVE-2026-22808 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. fleetdm/fleet is open source device management software. Prior to versions 4.78.2, 4.77.1, 4.76.2, 4.75.2, and 4.53.3, if Windows MDM is enabled, an unauthenticated attacker can exploit this XSS vulnerability to steal a Fleet administrator's authentication token (FLEET::auth_token) from localStorage. EPSS estimates a 0.21% chance of exploitation in the next 30 days.

Description

fleetdm/fleet is open source device management software. Prior to versions 4.78.2, 4.77.1, 4.76.2, 4.75.2, and 4.53.3, if Windows MDM is enabled, an unauthenticated attacker can exploit this XSS vulnerability to steal a Fleet administrator's authentication token (FLEET::auth_token) from localStorage. This could allow unauthorized access to Fleet, including administrative access, visibility into device data, and modification of configuration. Versions 4.78.2, 4.77.1, 4.76.2, 4.75.2, and 4.53.3 fix the issue. If an immediate upgrade is not possible, affected Fleet users should temporarily disable Windows MDM.

Metrics

CVSS 3.1
5.4/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

CVSS 4.0
5.5/10

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability
0.21%

11.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
FleetdmFleet< 4.53.3
FleetdmFleet>= 4.75.0, < 4.75.2
FleetdmFleet>= 4.76.0, < 4.76.2
FleetdmFleet>= 4.78.0, < 4.78.2
FleetdmFleet4.77.0

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-22808?
fleetdm/fleet is open source device management software. Prior to versions 4.78.2, 4.77.1, 4.76.2, 4.75.2, and 4.53.3, if Windows MDM is enabled, an unauthenticated attacker can exploit this XSS vulnerability to steal a Fleet administrator's authentication token (FLEET::auth_token) from localStorage. This could allow unauthorized access to Fleet, including administrative access, visibility into device data, and modification of configuration. Versions 4.78.2, 4.77.1, 4.76.2, 4.75.2, and 4.53.3 fix the issue. If an immediate upgrade is not possible, affected Fleet users should temporarily disable Windows MDM.
How severe is CVE-2026-22808?
CVE-2026-22808 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.21% probability of exploitation in the next 30 days.
How do I fix CVE-2026-22808?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-22808?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST