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Fencer Vulns
medium 5.4

CVE-2026-22808 json

Fleet Windows MDM endpoint has a Cross-site Scripting vulnerability

published 2026-01-20 9 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-3350 , GHSA-gfpw-jgvr-cw4j , GO-2026-4336

cvss
5.4
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 16%
public exploits
0
none known

Summary

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.

Patch / fix

  • go github.com/fleetdm/fleet 4.75.2, 4.76.2, 4.77.1, 4.78.2
  • go github.com/fleetdm/fleet/v4 4.43.5-0.20260111020427-0e6c790803d1, 4.75.2, 4.76.2, 4.77.1, 4.78.2
  • fleetdm fleet 4.53.3, 4.76.2, 4.77.1, 4.78.2
  • govulncheck-vulndb openSUSE Leap 15.6 0.0.20260205T172317-150000.1.146.1

suse advisories SUSE-SU-2026:0403-1

  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1

opensuse advisories openSUSE-SU-2026:21483-1

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
9 mo ago

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 16% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 5.5 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
CNA 4.0 5.5 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
NVD 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Affected packages

ecosystem package affected fixed in
go github.com/fleetdm/fleet
>=4.78.0, <4.78.2
>=4.77.0, <4.77.1
>=4.76.0, <4.76.2
>=4.75.0, <4.75.2
4.78.2
4.77.1
4.76.2
4.75.2
go github.com/fleetdm/fleet/v4
<4.43.5-0.20260111020427-0e6c790803d1
>=4.75.0, <4.75.2
>=4.76.0, <4.76.2
>=4.77.0, <4.77.1
>=4.78.0, <4.78.2
4.43.5-0.20260111020427-0e6c790803d1
4.75.2
4.76.2
4.77.1
4.78.2

Affected products

  • fleetdm fleet

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.