How severe is CVE-2026-34391?

CVE-2026-34391 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-34391 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (6th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-34391?

CVE-2026-34391 affects Fleetdm Fleet. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-34391?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-34391 have an EU (EUVD) identifier?

Yes. CVE-2026-34391 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-16799.

When was CVE-2026-34391 published?

CVE-2026-34391 was published on 2026-03-27 and last updated on 2026-06-17.

CVE-2026-34391

CVE-2026-34391 is a high-severity vulnerability in Fleetdm Fleet with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-488.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 6.6
EPSS exploit prediction: 0% (6th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-16799
Weakness: CWE-488
Affected product: Fleetdm Fleet
Published: 2026-03-27
Last modified: 2026-06-17

Description

Fleet is open source device management software. Prior to 4.81.1, a vulnerability in Fleet's Windows MDM command processing allows a malicious enrolled device to access MDM commands intended for other devices, potentially exposing sensitive configuration data such as WiFi credentials, VPN secrets, and certificate payloads across the entire Windows fleet. Version 4.81.1 patches the issue.

Frequently asked questions

What is CVE-2026-34391?: Fleet is open source device management software. Prior to 4.81.1, a vulnerability in Fleet's Windows MDM command processing allows a malicious enrolled device to access MDM commands intended for other devices, potentially exposing sensitive configuration data such as WiFi credentials, VPN secrets, and certificate payloads across the entire Windows fleet. Version 4.81.1 patches the issue.
How severe is CVE-2026-34391?: CVE-2026-34391 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-34391 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (6th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-34391?: CVE-2026-34391 affects Fleetdm Fleet. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-34391?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-34391 have an EU (EUVD) identifier?: Yes. CVE-2026-34391 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-16799.
When was CVE-2026-34391 published?: CVE-2026-34391 was published on 2026-03-27 and last updated on 2026-06-17.

References

https://github.com/fleetdm/fleet/security/advisories/GHSA-wg7j-pcc3-h4rh

Affected products (1)

cpe:2.3:a:fleetdm:fleet:*:*:*:*:*:*:*:*

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