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. The 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. 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 epmd.service and epmd.socket and requiring manual operator intervention to recover. This issue affects OTP from OTP 17.0 before OTP 27.3.4.15, OTP 28.5.0.4, and OTP 29.0.4, corresponding to erts from 6.0 before 15.2.7.11, 16.4.0.4, and 17.0.4.
Affected products
erlang: erlang\/otp; erlang: erts
References6
- github.com/erlang/otp/security/advisories/GHSA-h6f3-hx58-xhj6 Vendor Advisory
- cna.erlef.org/cves/CVE-2026-42792.html PatchThird Party Advisory
- github.com/erlang/otp/commit/865d203e4a6a8f44179eced9e1428f9259… Patch
- osv.dev/vulnerability/EEF-CVE-2026-42792 PatchThird Party Advisory
- github.com/erlang/otp/commit/07b8f441ca711f9812fad9e9115bab3c3a…
- www.erlang.org/doc/system/versions.html#order-of-versions Release Notes
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 4.0
-
6.3
MEDIUM
Score source: CNA
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 40 · as of 13 November 2026
- CWE
- CWE-755CWE-770
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.