CVE-2026-24000
This allowed authenticated and unauthenticated clients to spoof their apparent IP address and bypass per-IP rate limiting controls.
Does this matter?
Lower severity and a low EPSS score (0.43%). Track it; it rarely justifies an emergency change on its own.
Description
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.
- CVSS 4.0
- 6.9 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.43% probability · 36th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-290
- Affected
- fleetdm/fleet
- Source
- security-advisories@github.com
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.