CVE-2025-46712Network attack vector

Message injection via unenforced strict key exchange

Published May 8, 2025 · Updated Jan 12, 2026

Expected behavior violation in Erlang/OTP SSH allows man-in-the-middle attackers to inject optional messages during initial key exchange. The SSH key-exchange state machine accepts SSH_MSG_DEBUG, SSH_MSG_IGNORE, or SSH_MSG_UNIMPLEMENTED after KEXINIT instead of terminating strict-KEX connections. Network position between client and server is required; upstream reports that these messages are usually ignored and identifies no immediate security impact.

CVSS severity3.7
Low
EPSS probability0.53%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Expected behavior violation in Erlang/OTP SSH allows man-in-the-middle attackers to inject optional messages during initial key exchange. The SSH key-exchange state machine accepts SSH_MSG_DEBUG, SSH_MSG_IGNORE, or SSH_MSG_UNIMPLEMENTED after KEXINIT instead of terminating strict-KEX connections. Network position between client and server is required; upstream reports that these messages are usually ignored and identifies no immediate security impact.

The record

CVE
CVE-2025-46712
Published
May 8, 2025
Updated
Jan 12, 2026
Vendor
Erlang
Product
Erlang/OTP
Classifications
CWE-440, T1557
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 8, 2025CVE publishedPublication date reported by the CVE source.
  2. Jan 12, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< OTP 25.3.2.21
  2. Affected versionversion=>= OTP 26.2.1, < OTP 26.2.5.12
  3. Affected versionversion=>= OTP 27.0, < OTP 27.3.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Erlang · Erlang/OTPversion=< OTP 25.3.2.21; version=>= OTP 26.2.1, < OTP 26.2.5.12; version=>= OTP 27.0, < OTP 27.3.4

Published CVSS scores

3.7GitHubCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-440Expected Behavior Violation
T1557Adversary-in-the-Middle

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo