CVE-2026-42792: Improper Handling of Exceptional Conditions vulnerability in Erlang OTP erts (epmd) allows an unauthenticated

This month

HIGH 7.5REMOTEUPGRADEUPGRADE

CVE-2026-42792 is a high-severity flaw (CVSS 7.5) affecting erlang\/otp, erts. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 th

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.4% (top 63%)
CISA exploited list	No
Weakness	CWE-755, CWE-770
Published	2026-07-27
Last modified	2026-10-24

Publisher (CNA): EEF · Vendor: erlang

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-27 16:17 UTCPublished CVE record published
2026-10-24 13:10 UTCUpdated Record last modified

erlang erlang\/otp UPGRADE

Affected: >= 17.0 and < 27.3.4 · >= 28.0 and < 28.5.0.4 · >= 29.0 and < 29.0.4

Fixed in: 27.3.4, 28.5.0.4, 29.0.4

Safe to downgrade to: a release before 17.0

1. Check installed version

apt-cache policy erlangotp || rpm -q erlangotp || erlangotp --version

2. UPGRADE to 27.3.4 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade erlangotp

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade erlangotp

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 17.0 (Debian / Ubuntu)

apt-cache madison erlangotp sudo apt install erlangotp=<VERSION_BEFORE_17.0> sudo apt-mark hold erlangotp

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list erlangotp sudo dnf downgrade erlangotp-<VERSION_BEFORE_17.0> sudo dnf versionlock add erlangotp

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

erlang erts UPGRADE

Affected: >= 6.0 and < 15.2.7.11 · >= 16.0 and < 16.4.0.4 · >= 17.0 and < 17.0.4

Fixed in: 15.2.7.11, 16.4.0.4, 17.0.4

Safe to downgrade to: a release before 6.0

1. Check installed version

apt-cache policy erts || rpm -q erts || erts --version

2. UPGRADE to 15.2.7.11 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade erts

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade erts

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 6.0 (Debian / Ubuntu)

apt-cache madison erts sudo apt install erts=<VERSION_BEFORE_6.0> sudo apt-mark hold erts

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list erts sudo dnf downgrade erts-<VERSION_BEFORE_6.0> sudo dnf versionlock add erts

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Exact fixes by distribution

Fedora ELN · ntpd-rs · FIXED · 1.7.2-3.eln159 · FEDORA-2026-57e4a99310 · source

sudo dnf upgrade --advisory=FEDORA-2026-57e4a99310

Fedora 46 · moby-engine · FIXED · 29.9.2-2.fc46 · FEDORA-2026-4856be87b3 · source

sudo dnf upgrade --advisory=FEDORA-2026-4856be87b3

Ubuntu 20.04 · erlang · FIXED · 1:22.2.7+dfsg-1ubuntu0.5+esm2

sudo apt update && sudo apt install --only-upgrade erlang dpkg --compare-versions "$(dpkg-query -W -f='${Version}' erlang)" ge "1:22.2.7+dfsg-1ubuntu0.5+esm2" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 22.04 · erlang · FIXED · 1:24.2.1+dfsg-1ubuntu0.7

sudo apt update && sudo apt install --only-upgrade erlang dpkg --compare-versions "$(dpkg-query -W -f='${Version}' erlang)" ge "1:24.2.1+dfsg-1ubuntu0.7" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 24.04 · erlang · FIXED · 1:25.3.2.8+dfsg-1ubuntu4.7

sudo apt update && sudo apt install --only-upgrade erlang dpkg --compare-versions "$(dpkg-query -W -f='${Version}' erlang)" ge "1:25.3.2.8+dfsg-1ubuntu4.7" && echo PATCHED || echo STILL-VULNERABLE

Debian 12 · erlang · NO FIX YET

Debian 13 · erlang · FIXED · 1:27.3.4.1+dfsg-1+deb13u3

sudo apt update && sudo apt install --only-upgrade erlang dpkg --compare-versions "$(dpkg-query -W -f='${Version}' erlang)" ge "1:27.3.4.1+dfsg-1+deb13u3" && echo PATCHED || echo STILL-VULNERABLE

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Write-up: cna.erlef.org/cves/CVE-2026-42792.html

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-42792?

erlang\/otp: upgrade to 27.3.4, 28.5.0.4, 29.0.4; erts: upgrade to 15.2.7.11, 16.4.0.4, 17.0.4. Exact commands for each OS are on this page.

Is CVE-2026-42792 being exploited?

CVE-2026-42792 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-42792 affect?

CVE-2026-42792 affects erlang\/otp, erts. Severity is high (CVSS 7.5). 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 funct

How urgent is CVE-2026-42792?

Priority 40/100. High severity; Remotely exploitable, no login, no user action

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References

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