CVE-2025-26618

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.

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.

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.

SSH SFTP packet size not verified properly in Erlang OTP. (CVE-2025-26618)

These are all security issues fixed in the erlang-27.2.4-2.1 package on the GA media of openSUSE Tumbleweed.

These are all security issues fixed in the erlang27-27.1.3-3.1 package on the GA media of openSUSE Tumbleweed.

This update for erlang fixes the following issues:

• CVE-2025-26618: Fixed SSH SFTP packet size not verified properly in Erlang OTP (bsc#1237467).

This update for erlang26 fixes the following issues:

• CVE-2025-26618: Fixed incorrect verification of SSH SFTP packet size in Erlang OTP (bsc#1237467)

It was discovered that Erlang incorrectly handled SFTP packet sizes. A remote attacker could possibly use this issue to cause Erlang to consume resources, resulting in a denial of service.

Wander Nauta discovered that Erlang incorrectly handled absolute paths when extracting zip archives. An attacker could possibly use this issue to write arbitrary files outside of the intended directory. This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2025-4748)

It was discovered that the Erlang SFTP server did not properly limit the size of packets. A remote attacker could possibly use this issue to cause Erlang to use excessive resources, leading to a denial of service. This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, and Ubuntu 18.04 LTS. (CVE-2025-26618)

It was discovered that the Erlang SSH server did not properly limit the length of algorithm names in key exchange messages. A remote attacker could possibly use this issue to cause Erlang to use excessive resources, leading to a denial of service. This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS, and Ubuntu 18.04 LTS. (CVE-2025-30211)

It was discovered that the Erlang TFTP server incorrectly handled certain file paths. A remote attacker could possibly use this issue to access files outside of the intended directory. (CVE-2026-21620)

It was discovered that the Erlang SFTP server incorrectly validated paths against the configured root directory. An authenticated user could possibly use this issue to access files outside of the root directory. (CVE-2026-23942)

It was discovered that the Erlang SSH server enabled zlib compression by default and did not limit the size of decompressed data. A remote attacker could possibly use this issue to cause Erlang to use excessive resources, leading to a denial of service. (CVE-2026-23943)

It was discovered that the Erlang HTTP server incorrectly applied directory access controls to CGI scripts served via script aliases. A remote attacker could possibly use this issue to bypass authentication and access protected CGI scripts. (CVE-2026-28808)

It was discovered that the Erlang DNS resolver used predictable transaction IDs and did not randomize source ports. A remote attacker could possibly use this issue to perform DNS cache poisoning attacks. This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-28810)

It was discovered that Erlang did not verify the signatures of designated OCSP responder certificates. A remote attacker could possibly use this issue to forge OCSP responses and bypass certificate revocation checks. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-32144)

It was discovered that the Erlang SFTP server incorrectly handled file attribute changes on open file handles. An authenticated user could possibly use this issue to modify the attributes of files outside of the root directory. (CVE-2026-32147)

It was discovered that Erlang incorrectly allowed non-CA certificates to act as intermediate certificate issuers. A remote attacker could possibly use this issue to forge certificate chains. (CVE-2026-42789)

It was discovered that Erlang incorrectly handled DNS name constraints during hostname verification. A remote attacker could possibly use this issue to bypass certificate validation. This issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-42790)

It was discovered that Erlang did not check the validity period of OCSP responder certificates. A remote attacker could possibly use this issue to forge OCSP responses using an expired responder certificate. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-42791)

It was discovered that Erlang incorrectly handled relative paths when extracting zip archives. An attacker could possibly use this issue to write arbitrary files outside of the intended directory. This issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-47078)

It was discovered that the Erlang SFTP server exposed absolute paths when reading symbolic links. An…