How severe is CVE-2026-34388?

CVE-2026-34388 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 none, integrity none, and availability high.

Is CVE-2026-34388 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-34388?

CVE-2026-34388 affects Fleetdm Fleet. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-34388?

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-2026-34388 have an EU (EUVD) identifier?

Yes. CVE-2026-34388 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-16795.

When was CVE-2026-34388 published?

CVE-2026-34388 was published on 2026-03-27 and last updated on 2026-06-17.

CVE-2026-34388

CVE-2026-34388 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-703.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 6.6
EPSS exploit prediction: 0% (18th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-16795
Weakness: CWE-703
Affected product: Fleetdm Fleet
Published: 2026-03-27
Last modified: 2026-06-17

Description

Fleet is open source device management software. Prior to 4.81.0, a denial-of-service vulnerability in Fleet's gRPC Launcher endpoint allows an authenticated host to crash the entire Fleet server process by sending an unexpected log type value. The server terminates immediately, disrupting all connected hosts, MDM enrollments, and API consumers. Version 4.81.0 patches the issue.

Frequently asked questions

What is CVE-2026-34388?: Fleet is open source device management software. Prior to 4.81.0, a denial-of-service vulnerability in Fleet's gRPC Launcher endpoint allows an authenticated host to crash the entire Fleet server process by sending an unexpected log type value. The server terminates immediately, disrupting all connected hosts, MDM enrollments, and API consumers. Version 4.81.0 patches the issue.
How severe is CVE-2026-34388?: CVE-2026-34388 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 none, integrity none, and availability high.
Is CVE-2026-34388 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (18th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-34388?: CVE-2026-34388 affects Fleetdm Fleet. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-34388?: 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-2026-34388 have an EU (EUVD) identifier?: Yes. CVE-2026-34388 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-16795.
When was CVE-2026-34388 published?: CVE-2026-34388 was published on 2026-03-27 and last updated on 2026-06-17.

References

https://github.com/fleetdm/fleet/security/advisories/GHSA-w254-4hp5-7cvv

Affected products (1)

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

More vulnerabilities in Fleetdm Fleet

CVE-2020-26276 — Critical (CVSS 10.0): Fleet is an open source osquery manager. In Fleet before version 3.5.1, due to issues in Go's standard library XML…
CVE-2026-26191 — Critical (CVSS 9.8): Fleet is open source device management software. Prior to version 4.81.0, a vulnerability in Fleet's software installer…
CVE-2026-34387 — Critical (CVSS 9.8): Fleet is open source device management software. Prior to 4.81.1, a command injection vulnerability in Fleet's software…
CVE-2026-23518 — Critical (CVSS 9.8): Fleet is open source device management software. In versions prior to 4.78.3, 4.77.1, 4.76.2, 4.75.2, and 4.53.3, a…
CVE-2026-34386 — High (CVSS 8.8): Fleet is open source device management software. Prior to 4.81.0, a SQL injection vulnerability in Fleet's MDM…
CVE-2026-29180 — High (CVSS 8.8): Fleet is open source device management software. Prior to 4.81.1, a broken access control vulnerability in Fleet's host…

All CVEs affecting Fleetdm Fleet →

Other CWE-703 vulnerabilities

CVE-2025-13026 — Critical (CVSS 9.8): Sandbox escape due to incorrect boundary conditions in the Graphics: WebGPU component. This vulnerability was fixed in…
CVE-2025-13023 — Critical (CVSS 9.8): Sandbox escape due to incorrect boundary conditions in the Graphics: WebGPU component. This vulnerability was fixed in…
CVE-2025-13022 — Critical (CVSS 9.8): Incorrect boundary conditions in the Graphics: WebGPU component. This vulnerability was fixed in Firefox 145 and…
CVE-2025-13021 — Critical (CVSS 9.8): Incorrect boundary conditions in the Graphics: WebGPU component. This vulnerability was fixed in Firefox 145 and…
CVE-2024-39815 — Critical (CVSS 9.1): Improper check or handling of exceptional conditions vulnerability affecting Vonets industrial wifi bridge relays…
CVE-2023-45927 — Critical (CVSS 9.1): S-Lang 2.3.2 was discovered to contain an arithmetic exception via the function tt_sprintf().

Browse all CWE-703 vulnerabilities →