{"id":"CVE-2026-42792","summary":"epmd permanent DoS via EMFILE on accept(2) in erts","details":"Improper Handling of Exceptional Conditions vulnerability in Erlang OTP erts (epmd) allows an unauthenticated remote attacker to permanently terminate the Erlang Port Mapper Daemon (epmd) via connection slot exhaustion.\n\nThe do_accept function in erts/epmd/src/epmd_srv.c calls epmd_cleanup_exit() when accept(2) returns EMFILE (per-process file descriptor limit reached) or ENFILE (system-wide file descriptor limit reached), rather than treating these as recoverable conditions. An attacker can exhaust epmd's file descriptor slots by holding many TCP connections open while periodically sending a single byte to reset the idle timeout, then causing accept(2) to return EMFILE, which kills the daemon. epmd has no per-source-IP connection cap, making the attack feasible from a single source.\n\nOn Debian/Ubuntu default packaging the impact is amplified: the systemd unit inherits a low file descriptor soft limit, and repeated daemon deaths trigger systemd's start-rate-limit, permanently failing both epmd.service and epmd.socket and requiring manual operator intervention to recover.\n\nThis issue affects OTP from OTP 17.0 before OTP 29.0.4, OTP 28.5.0.4 and OTP 27.3.4.15.","aliases":["EEF-CVE-2026-42792","GHSA-h6f3-hx58-xhj6"],"modified":"2026-08-01T03:46:22.674795093Z","published":"2026-07-27T14:58:24.426Z","database_specific":{"cwe_ids":["CWE-755","CWE-770"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42792.json","unresolved_ranges":[{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"6.0"},{"fixed":"*"},{"introduced":"17.0"},{"fixed":"*"},{"introduced":"07b8f441ca711f9812fad9e9115bab3c3aa92f79"},{"fixed":"865d203e4a6a8f44179eced9e1428f9259e4a3bb"}]}],"cna_assigner":"EEF"},"references":[{"type":"WEB","url":"https://cna.erlef.org/cves/CVE-2026-42792.html"},{"type":"WEB","url":"https://github.com"},{"type":"WEB","url":"https://osv.dev/vulnerability/EEF-CVE-2026-42792"},{"type":"WEB","url":"https://www.erlang.org/doc/system/versions.html#order-of-versions"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42792.json"},{"type":"ADVISORY","url":"https://github.com/erlang/otp/security/advisories/GHSA-h6f3-hx58-xhj6"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-42792"},{"type":"FIX","url":"https://github.com/erlang/otp/commit/865d203e4a6a8f44179eced9e1428f9259e4a3bb"},{"type":"PACKAGE","url":"https://github.com/erlang/otp"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/erlang/otp","events":[{"introduced":"0"},{"introduced":"9e6f6742c4d9e9915ee8af0dcb7d97cf1f836116"},{"introduced":"550d7b7898706c7822362c42e7b93120c1d1f29a"},{"fixed":"8def54e66dfdd41c535272794d49cc633f596d22"},{"fixed":"6cfd400a2379163a2802f376d3b3d02f815d34c0"},{"fixed":"1259612946cb36a8bf9614b289090bb32fbcbeb2"},{"fixed":"865d203e4a6a8f44179eced9e1428f9259e4a3bb"}],"database_specific":{"source":["CPE_FIELD","REFERENCES"],"extracted_events":[{"introduced":"0"},{"fixed":"27.3.4.15"},{"introduced":"28.0"},{"fixed":"28.5.0.4"},{"introduced":"29.0"},{"fixed":"29.0.4"}]}}],"versions":["OTP-29.0.3","OTP-28.5.0.3","OTP-27.3.4.14","patch-base-28","OTP-28.5","patch-base-27","OTP-27.3.4","OTP-27.3.4.13","OTP-28.5.0.2","OTP-29.0.2","OTP-28.4","OTP-27.3.4.12","OTP-28.5.0.1","OTP-29.0.1","OTP-29.0","OTP-27.3.4.9","OTP-27.0","OTP-27.3.4.11","OTP-27.3.4.10","OTP-28.0","OTP-27.3.4.8","OTP-27.3.4.6","OTP-27.3.4.7","OTP-27.3","OTP-27.3.4.5","OTP-27.3.4.4","OTP-28.1","OTP-27.3.4.3","OTP-27.3.3","OTP-27.3.4.2","OTP-26.0","OTP-25.0","OTP-27.3.4.1","OTP-27.3.2","OTP-27.2","OTP-27.3.1","OTP-27.1","OTP-27.0-rc3","OTP-27.0-rc2","OTP-27.0-rc1","OTP-24.0","OTP-26.0-rc3","OTP-26.0-rc2","OTP-26.0-rc1","OTP-23.0","OTP-21.0","OTP-25.0-rc3","OTP-25.0-rc2","OTP-25.0-rc1","OTP-22.0","OTP-24.0-rc3","OTP-24.0-rc2","OTP-24.0-rc1","OTP-23.0-rc3","OTP-23.0-rc2","OTP-23.0-rc1","OTP-20.0","OTP-22.0-rc3","OTP-22.0-rc2","OTP-22.0-rc1","OTP-19.0","OTP-21.0-rc2","OTP-18.0","OTP-21.0-rc1","OTP-17.0","OTP-20.0-rc2","OTP-20.0-rc1","OTP-19.0-rc2","OTP-19.0-rc1","OTP_R16B","OTP-18.0-rc1","OTP_17.0-rc2","OTP_17.0-rc1","OTP_R13B03","OTP_R16A_RELEASE_CANDIDATE","OTP_R14B03","OTP_R15B","OTP_R15A","OTP_R14B02","OTP_R14B01","OTP_R14B","OTP_R13B04","OTP_R14A"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-42792.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"}]}