{"id":"CVE-2026-24000","state":"PUBLISHED","title":"Fleet has a rate limiting bypass via untrusted client IP headers","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.","publishedAt":"2026-05-14T18:56:39.139Z","updatedAt":"2026-05-14T19:41:20.490Z","severity":{"score":6.9,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["fleetdm fleet"],"affected":[{"vendor":"fleetdm","product":"fleet","versions":[{"version":"< 4.80.1","status":"affected"}]}],"references":["https://github.com/fleetdm/fleet/security/advisories/GHSA-j8h8-75h3-jg53","https://github.com/fleetdm/fleet/releases/tag/fleet-v4.80.1"],"weaknesses":["CWE-290"],"ingestedAt":"2026-10-29T20:11:21.040Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/24xxx/CVE-2026-24000.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-24000","state":"PUBLISHED","datePublished":"2026-05-14T18:56:39.139Z","dateUpdated":"2026-05-14T19:41:20.490Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-01-19T18:49:20.658Z"},"containers":{"cna":{"title":"Fleet has a rate limiting bypass via untrusted client IP headers","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"fleetdm","product":"fleet","versions":[{"version":"< 4.80.1","status":"affected"}]}],"references":[{"url":"https://github.com/fleetdm/fleet/security/advisories/GHSA-j8h8-75h3-jg53","name":"https://github.com/fleetdm/fleet/security/advisories/GHSA-j8h8-75h3-jg53","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/fleetdm/fleet/releases/tag/fleet-v4.80.1","name":"https://github.com/fleetdm/fleet/releases/tag/fleet-v4.80.1","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":6.9,"baseSeverity":"MEDIUM","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-290","lang":"en","description":"CWE-290: Authentication Bypass by Spoofing","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-05-14T18:56:39.139Z"},"source":{"advisory":"GHSA-j8h8-75h3-jg53","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-14T19:41:10.742607Z","id":"CVE-2026-24000","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-05-14T19:41:20.490Z"}}]}}}