{"id":"GHSA-j8h8-75h3-jg53","revision":"4602c7200d6246e6a6485ab8dee2c782","records":[{"revision":"4602c7200d6246e6a6485ab8dee2c782","observedAt":"2026-10-24T13:19:41.952+00:00","statement":{"source":"osv","id":"GHSA-j8h8-75h3-jg53","aliases":["CVE-2026-24000","GO-2026-5455"],"title":"Fleet has a rate limiting bypass via untrusted client IP headers","description":"### Impact\n\nFleet 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.\n\nFleet determines a client’s public IP address using HTTP headers such as:\n- X-Forwarded-For\n- X-Real-IP\n- True-Client-IP\n\nThese 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.\n\nThis could allow an attacker to bypass per-IP rate limits and increase the effectiveness of brute-force or password-spraying attempts against authentication endpoints.\n\nThis issue does not allow authentication bypass, privilege escalation, data exposure, or remote code execution on its own.\n\n### Workarounds\n\nRun Fleet behind a trusted reverse proxy or load balancer that overwrites client IP headers.\n\n### For more information\n\nIf you have any questions or comments about this advisory:\n\nEmail us at [security@fleetdm.com](mailto:security@fleetdm.com)\nJoin #fleet in [osquery Slack](https://join.slack.com/t/osquery/shared_invite/zt-h29zm0gk-s2DBtGUTW4CFel0f0IjTEw)\n\n### Credits\n\nWe thank @fuzzztf for responsibly reporting this issue.","state":0,"publishedAt":"2026-05-14T13:13:39+00:00","modifiedAt":"2026-06-25T23:11:31.6738193+00:00","affected":[{"ecosystem":"Go","name":"github.com/fleetdm/fleet/v4","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"},{"kind":"fixed","version":"4.80.1"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","score":null,"severity":null},{"system":"CVSS_V4","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","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"MODERATE"}],"references":["https://github.com/fleetdm/fleet/security/advisories/GHSA-j8h8-75h3-jg53","https://nvd.nist.gov/vuln/detail/CVE-2026-24000","https://github.com/fleetdm/fleet","https://github.com/fleetdm/fleet/releases/tag/fleet-v4.80.1"],"sourceUrl":"https://github.com/advisories/GHSA-j8h8-75h3-jg53","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-j8h8-75h3-jg53","identifiers":["GHSA-j8h8-75h3-jg53","CVE-2026-24000","GO-2026-5455"]},"retained":false,"historicalAffected":[]}],"coverage":[]}