{"api_version":"1","generated_at":"2026-07-27T20:48:36+00:00","cve":"CVE-2026-42792","urls":{"html":"https://cve.report/CVE-2026-42792","api":"https://cve.report/api/cve/CVE-2026-42792.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-42792","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-42792"},"summary":{"title":"epmd permanent DoS via EMFILE on accept(2) in erts","description":"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.","state":"PUBLISHED","assigner":"EEF","published_at":"2026-07-27 16:17:06","updated_at":"2026-07-27 18:16:54"},"problem_types":["CWE-755","CWE-770","CWE-755 CWE-755 Improper Handling of Exceptional Conditions","CWE-770 CWE-770 Allocation of Resources Without Limits or 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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 <tt>accept(2)</tt> to return <tt>EMFILE</tt>, which kills the daemon. epmd has no per-source-IP connection cap, making the attack feasible from a single source.</p><p>On 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 <tt>epmd.service</tt> and <tt>epmd.socket</tt> and requiring manual operator intervention to recover.</p><p>This issue affects OTP from OTP 17.0 before OTP&nbsp;29.0.4, OTP&nbsp;28.5.0.4 and OTP&nbsp;27.3.4.15.</p>"}],"value":"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."}],"impacts":[{"capecId":"CAPEC-227","descriptions":[{"lang":"en","value":"CAPEC-227 Sustained Client 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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.","Type":"Description","Title":"epmd permanent DoS via EMFILE on accept(2) in erts"}]}}}