CVE-2025-26618 HIGH

CVE-2025-26618: SSH SFTP packet size not verified properly in Erlang OTP

Vendor Erlang
Product otp
Weakness CWE-789
Published February 20, 2025
Last update November 3, 2025

CVSS base score

7.0/10
Attack vector Network
Attack complexity High
Privileges required Low
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H

What the vulnerability does

01Description

Erlang is a programming language and runtime system for building massively scalable soft real-time systems with requirements on high availability. OTP is a set of Erlang libraries, which consists of the Erlang runtime system, a number of ready-to-use components mainly written in Erlang. Packet size is not verified properly for SFTP packets. As a result when multiple SSH packets (conforming to max SSH packet size) are received by ssh, they might be combined into an SFTP packet which will exceed the max allowed packet size and potentially cause large amount of memory to be allocated. Note that situation described above can only happen for successfully authenticated users after completing the SSH handshake. This issue has been patched in OTP versions 27.2.4, 26.2.5.9, and 25.3.2.18. There are no known workarounds for this vulnerability.

Key dates

02Disclosure timeline

February 20, 2025 CVE published
November 3, 2025 Record updated