CVE-2026-42792

NameCVE-2026-42792
DescriptionImproper 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 29.0.4, OTP 28.5.0.4 and OTP 27.3.4.15.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
erlang (PTS)bullseye1:23.2.6+dfsg-1+deb11u1vulnerable
bullseye (security)1:23.2.6+dfsg-1+deb11u4vulnerable
bookworm1:25.2.3+dfsg-1+deb12u4vulnerable
bookworm (security)1:25.2.3+dfsg-1+deb12u1vulnerable
trixie1:27.3.4.1+dfsg-1+deb13u2vulnerable
forky, sid1:29.0.3+dfsg-1vulnerable

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
erlangsource(unstable)(unfixed)

Notes

https://github.com/erlang/otp/security/advisories/GHSA-h6f3-hx58-xhj6
https://cna.erlef.org/cves/CVE-2026-42792.html
https://osv.dev/vulnerability/EEF-CVE-2026-42792
Fixed by; https://github.com/erlang/otp/commit/865d203e4a6a8f44179eced9e1428f9259e4a3bb (OTP-29.0.4, OTP-28.5.0.4, OTP-27.3.4.15)

Search for package or bug name: Reporting problems