{"id":"GHSA-x67p-9m2r-fxqv","revision":"abb46b5bf75048c7bbfbcaf0330ca541","records":[{"revision":"abb46b5bf75048c7bbfbcaf0330ca541","observedAt":"2026-10-24T13:19:41.952+00:00","statement":{"source":"osv","id":"GHSA-x67p-9m2r-fxqv","aliases":["CVE-2026-26062","GO-2026-5744"],"title":"Fleet server may terminate unexpectedly when handling certain gRPC requests","description":"### Summary\n\nFleet contained a denial-of-service (DoS) issue in the gRPC Launcher `PublishLogs` endpoint. In affected versions, certain unexpected input values were not handled gracefully, which could cause the Fleet server process to terminate while processing an authenticated request from an enrolled Launcher host.\n\n### Impact\n\nAn authenticated attacker with access to any enrolled Launcher node key could cause an immediate and complete denial of service by sending a single gRPC request to the `PublishLogs` endpoint.\n\nThis vulnerability impacts **availability only**. There is:\n\n- No exposure of sensitive data\n- No authentication bypass\n- No privilege escalation\n- No integrity impact\n\n### Workarounds\n\nIf upgrading immediately is not possible, the following mitigations can reduce exposure:\n\n- Restrict network access to the Fleet gRPC endpoint where feasible (for example, limiting inbound access to known host IP ranges).\n- Deploy Fleet behind infrastructure that terminates or filters gRPC traffic if Launcher log ingestion is not required.\n- Monitor for repeated Fleet process crashes or unexpected restarts indicating potential exploitation.\n\n### For More Information\n\nIf you have any questions or concerns about this advisory, please contact us at:\n\nEmail us at [security@fleetdm.com](mailto:security@fleetdm.com)\n\n### Credits\n\nWe thank @fuzzztf for responsibly reporting this issue.","state":0,"publishedAt":"2026-05-14T13:17:18+00:00","modifiedAt":"2026-06-25T23:11:19.1358103+00:00","affected":[{"ecosystem":"Go","name":"github.com/fleetdm/fleet/v4","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"},{"kind":"fixed","version":"4.81.0"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V4","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"HIGH"}],"references":["https://github.com/fleetdm/fleet/security/advisories/GHSA-x67p-9m2r-fxqv","https://nvd.nist.gov/vuln/detail/CVE-2026-26062","https://github.com/fleetdm/fleet","https://github.com/fleetdm/fleet/releases/tag/fleet-v4.81.0"],"sourceUrl":"https://github.com/advisories/GHSA-x67p-9m2r-fxqv","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-x67p-9m2r-fxqv","identifiers":["GHSA-x67p-9m2r-fxqv","CVE-2026-26062","GO-2026-5744"]},"retained":false,"historicalAffected":[]}],"coverage":[]}