CVE-2025-32433: Erlang/OTP SSH server unauthenticated remote code execution

Exploited in the wild Critical 10.0 EPSS 98.9% Erlang/OTP

The SSH server in Erlang/OTP mishandles SSH protocol messages so that an attacker with network access can run commands without valid credentials, giving full remote code execution. Every application that runs an SSH daemon built on the Erlang/OTP ssh library is affected, including products from Cisco and others (CISA). Fixed in OTP-27.3.3, OTP-26.2.5.11 and OTP-25.3.2.20; CISA added it to KEV on 9 June 2025.

CVE-2025-32433CVE identifier
10.0CVSS 3.1 base score (critical)
2025-06-09added to CISA's exploited list (US federal deadline 2025-06-30)
98.9%EPSS: chance of exploitation in the next 30 days (higher than 100% of CVEs)
2025-04-16published

What do these terms mean? CVE · CVSS score · exploited (KEV) · EPSS · backported fix · all terms

What to do now

Check whether you run Erlang/OTP and which version (commands below).
Install the fixed version for your system: see “Patch it” below.
Restart every Erlang/OTP application (the BEAM VM) so the patched ssh library is loaded; vendor products embedding OTP need the vendor's update.
If you cannot patch today, apply the temporary mitigation below and patch as soon as possible.
Because this flaw is being exploited, also check the server for signs of compromise.

Affected and fixed versions

Affected:

OTP 27.0-rc1 before 27.3.3
OTP 26.0-rc1 before 26.2.5.11
OTP before 25.3.2.20 (17.0 and later; older releases are likely affected too)
ssh application 3.0.1 and later before 5.2.10, 5.1.4.8, 4.15.3.12

Fixed in:

OTP-27.3.3
OTP-26.2.5.11
OTP-25.3.2.20
ssh 5.2.10
ssh 5.1.4.8
ssh 4.15.3.12

Am I affected?

dpkg -l erlang-ssh erlang-base | grep ^ii   # Debian/Ubuntu
erl -noshell -eval 'io:format("~s~n",[erlang:system_info(otp_release)]), halt().'
sudo ss -ltnp | grep beam   # listening Erlang VMs (look for an SSH port)

Patch it

Use the commands for your system. Distribution packages often keep an older version number with the fix backported, so compare with the fixed package versions in the table below, not only with the upstream version.

Debian

sudo apt update
sudo apt install --only-upgrade 'erlang*'
# restart every Erlang application (e.g. RabbitMQ, ejabberd)

Ubuntu

sudo apt update
sudo apt install --only-upgrade 'erlang*'
# restart every Erlang application

RHEL, AlmaLinux, Rocky, Oracle

not in RHEL/EPEL: Erlang Solutions or RabbitMQ repo

Fedora

sudo dnf upgrade --refresh erlang

SUSE / openSUSE

sudo zypper refresh
sudo zypper update erlang

Amazon Linux

not in distro repos: vendor repository

Arch Linux

sudo pacman -Syu

Alpine

apk update && apk upgrade erlang28 (or erlang27)

FreeBSD

pkg update && pkg upgrade erlang (or erlang-runtime27/28)

Built from source

# rebuild/redeploy your release on OTP-27.3.3, OTP-26.2.5.11 or OTP-25.3.2.20 or later

General update steps for every system are on the Linux and Unix & BSD pages; after updating, see which services to restart.

Fix status in Linux distributions

Release	Package	Status	Fixed version / advisory
Debian 12	`erlang`	fixed	`1:25.2.3+dfsg-1+deb12u1`
Debian 13	`erlang`	fixed	`1:27.3.3+dfsg-1`
Debian testing	`erlang`	fixed	`1:27.3.3+dfsg-1`
Ubuntu 20.04 (ESM)	`erlang`	fixed	`1:22.2.7+dfsg-1ubuntu0.5`
Ubuntu 22.04	`erlang`	fixed	`1:24.2.1+dfsg-1ubuntu0.4`
Ubuntu 24.04	`erlang`	fixed	`1:25.3.2.8+dfsg-1ubuntu4.3`
Ubuntu 18.04 (ESM)	`erlang`	fixed	`1:20.2.2+dfsg-1ubuntu2+esm1`
Debian 13 (trixie)	`erlang`	fixed	`1:27.3.3+dfsg-1`
Debian 12 (bookworm)	`erlang`	fixed	`1:25.2.3+dfsg-1+deb12u1 (DSA-5906-1)`
Debian 11 (bullseye)	`erlang`	fixed	`1:23.2.6+dfsg-1+deb11u2 (DLA-4132-1)`
Ubuntu 24.04 LTS	`erlang`	fixed	`1:25.3.2.8+dfsg-1ubuntu4.3 (USN-7443-1)`
Ubuntu 22.04 LTS	`erlang`	fixed	`1:24.2.1+dfsg-1ubuntu0.4 (USN-7443-1)`
Ubuntu 20.04 LTS	`erlang`	fixed	`1:22.2.7+dfsg-1ubuntu0.5 (USN-7443-1)`
Ubuntu 18.04 LTS (ESM)	`erlang`	fixed	`1:20.2.2+dfsg-1ubuntu2+esm1 (USN-7443-3)`

From the Debian security tracker, Ubuntu CVE tracker and Red Hat Security Data API, refreshed every few hours.

If you cannot patch yet

Until you can upgrade, disable the Erlang/OTP SSH server or block access to it with firewall rules (Erlang advisory).

CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

This vulnerability affects a common open-source project, third-party library, or a protocol used by different products. For more information, please see: https://github.com/erlang/otp/security/advisories/GHSA-37cp-fgq5-7wc2 ; https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-erlang-otp-ssh-xyZZy ; https://nvd.nist.gov/vuln/detail/CVE-2025-32433

Sources

Page generated automatically from official sources on 2026-11-03 18:05 UTC and reviewed by an editor. Always confirm with your vendor's advisory.