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TI-2026-19339 Aliases CVE-2026-24000GHSA-j8h8-75h3-jg53

Fleet has a rate limiting bypass via untrusted client IP headers

Priority LOW 37CWE-290Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Security bypass
Confidentiality · integrity · availability
None · Low · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-290.

Summary

Fleet is open source device management software. Prior to version 4.80.1, Fleet trusted client-supplied IP address headers when determining the source IP for incoming requests. This allowed authenticated and unauthenticated clients to spoof their apparent IP address and bypass per-IP rate limiting controls. Fleet determines a client’s public IP address using HTTP headers such as X-Forwarded-For, X-Real-IP, and/or True-Client-IP. These headers were trusted without validation. An attacker could supply arbitrary values in these headers, causing Fleet to treat each request as originating from a different IP address. This could allow an attacker to bypass per-IP rate limits and increase the effectiveness of brute-force or password-spraying attempts against authentication endpoints. This issue does not allow authentication bypass, privilege escalation, data exposure, or remote code execution on its own. Version 4.80.1 contains a patch. As a workaround, run Fleet behind a trusted reverse proxy or load balancer that overwrites client IP headers.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0043 37th percentileScored 2026-11-07
Fix Fixed fleet (fleetdm): 4.80.1github.com/fleetdm/fleet/v4 (Go): 4.80.1

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

VendorProductAffected versionsFixed inStatusSource
fleetdmfleetbefore 4.80.14.80.1Patch availableCNA
—github.com/fleetdm/fleet/v4 (Go)before 4.80.14.80.1Patch availableGHSA-j8h8-75h3-jg53
  • fleet Vendorfleetdm Affected before 4.80.1 Fixed in 4.80.1 Patch available CNA
  • github.com/fleetdm/fleet/v4 (Go) Vendor— Affected before 4.80.1 Fixed in 4.80.1 Patch available GHSA-j8h8-75h3-jg53

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:fleetdm:fleet:*:*:*:*:*:*:*:*before 4.80.1Vulnerablefleetdm
  • cpe:2.3:a:fleetdm:fleet:*:*:*:*:*:*:*:* Versions before 4.80.1 Vulnerable ·fleetdm

Remediation

  • Fix · CNA fleet (fleetdm) Fixed in 4.80.1
  • Fix · GHSA-j8h8-75h3-jg53 github.com/fleetdm/fleet/v4 (Go) Fixed in 4.80.1 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-24000
  2. 2026-10-03 Alias added: GHSA-j8h8-75h3-jg53

References

Advisory 2

Other 2

  • 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-2026-21066 Fleet server may terminate unexpectedly when handling certain gRPC requests CVSS 4.0HIGH 8.7
  • TI-2026-21065 Fleet's unbounded request body read allows remote Denial of Service CVSS 4.0HIGH 8.7
  • TI-2026-20084 Fleet Windows MDM Azure AD JWT Authentication Bypass CVSS 4.0HIGH 8.2
See all 31 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences