Unbounded gzip decompression in Fleet enables denial of service
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
Summary
Fleet before 4.83.0 contains a denial of service flaw in how it handles gzip-compressed request bodies. A missing limit on decompressed size lets an unauthenticated remote attacker send small, highly compressed requests that expand in memory during decoding, exhausting server memory and crashing the Fleet instance. The flaw is tracked under CWE-409.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
Fleet before 4.83.0 contains a denial of service vulnerability that allows unauthenticated attackers to exhaust server memory by sending gzip-compressed request bodies. Attackers can send small, highly compressed requests with Content-Encoding: gzip to unauthenticated endpoints that expand during decoding, crashing the entire Fleet instance.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
Upgrade Fleet to version 4.83.0 or later.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
- Fix · CNA fleet (fleetdm) Fixed in 4.83.0
Timeline
- 2026-10-18 Threatist record created from CVE-2026-111924
- 2026-10-18 Alias added: GHSA-7fp2-q7fp-2qwf
- 2026-10-18 Priority changed: MEDIUM → LOW
- 2026-10-20 CISA SSVC decision points changed
- 2026-10-20 Priority changed: LOW → MEDIUM
References
More fleetdm vulnerabilities
- TI-2026-29868 Fleet: Cross-Team Policy Data Exposure via Global Policy Read Endpoint CVSS 3.1MEDIUM 4.3
- TI-2025-20341 SAML authentication vulnerability due to improper SAML response validation CVSS 4.0CRITICAL 9.3
- TI-2026-65639 Fleet before 4.87.0 Authentication Bypass via Device Identifiers CVSS 4.0CRITICAL 9.3
- TI-2026-18942 Fleet has a JWT signature bypass vulnerability in Azure AD MDM enrollment CVSS 4.0CRITICAL 9.3
- TI-2020-16097 SAML authentication vulnerability in Fleet CVSS 3.1CRITICAL 10.0
- TI-2026-76129 Unbounded recursion in Fleet Apple MDM enrollment lets attackers crash server CVSS 4.0HIGH 8.7
Sources
- CVE-2026-111924 · CVE Program
- CVE-2026-111924 · NVD
- FIRST EPSS
- GHSA-7fp2-q7fp-2qwf · GitHub Advisory Database · CC BY 4.0
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