CVE-2025-26618: SSH SFTP packet size not verified properly in Erlang OTP
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.
Other sources
SSH SFTP packet size not verified properly in Erlang OTP
— Microsoft
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/erlangto a version that resolves this vulnerability.Fixed in 1:27.2.4+dfsg-1 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 26.2.5.9-1 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 25.2-3 - Upgrade
Upgrade
Erlang/OTPto a version that resolves this vulnerability.Fixed in 27.2.4 - Upgrade
Upgrade
Erlang/OTPto a version that resolves this vulnerability.Fixed in 26.2.5.9 - Upgrade
Upgrade
Erlang/OTPto a version that resolves this vulnerability.Fixed in 25.3.2.18
Event History
Frequently Asked Questions
What is the severity of CVE-2025-26618?
CVE-2025-26618 is classified as a high severity vulnerability due to potential exploitation risks.
How do I fix CVE-2025-26618?
To mitigate CVE-2025-26618, update Erlang OTP to version 27.2.4 or later, or 26.2.5.10 and beyond.
What software is affected by CVE-2025-26618?
CVE-2025-26618 affects Erlang OTP versions up to 27.2.4, 26.2.5.9, and 25.3.2.18.
What types of systems are impacted by CVE-2025-26618?
CVE-2025-26618 impacts massively scalable soft real-time systems that require high availability.
What are the implications of CVE-2025-26618 for developers?
Developers using affected versions of Erlang OTP should prioritize updating to secure their applications against potential exploits.