CVE-2026-34388 json
Fleet vulnerable to Denial of Service via unhandled gRPC log type in launcher endpoint
published 7mo ago modified 15d ago also EUVD-2026-16795 , GHSA-w254-4hp5-7cvv , GO-2026-4915
- cvss
- 7.5
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 19%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- go github.com/fleetdm/fleet/v4 4.81.0
- fleetdm fleet 4.81.0
- govulncheck-vulndb openSUSE Leap 15.6 0.0.20260402T184258-150000.1.158.1
suse advisories SUSE-SU-2026:1205-1
- govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
opensuse advisories openSUSE-SU-2026:21483-1
Is CVE-2026-34388 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 7mo ago
Exploit prediction
0.27% chance of exploitation in the next 30 days, higher than 19% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 6.6 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U |
| CNA | 4.0 | 6.6 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/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 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| go | github.com/fleetdm/fleet/v4 | <4.81.0 |
4.81.0 |
Affected products
- fleetdm fleet
Classification
- Weakness
-
- CWE-703 Improper Check or Handling of Exceptional Conditions
References
-
github.com
/fleetdm/fleet/security/advisories/GHSA-w254-4hp5-7cvv
web, vendor-advisory, advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-34388
advisory
-
github.com
/fleetdm/fleet
package
Sources
- CVE List CVE-2026-34388
- GitHub Advisory GHSA-w254-4hp5-7cvv
- NVD CVE-2026-34388
- OSV GO-2026-4915
Fencer Intel 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.