CVE-2025-30211

Erlang is a general-purpose programming language and runtime environment. Erlang has built-in support for concurrency, distribution and fault tolerance. Erlang is used in several large telecommunication systems from Ericsson.

Security Fix(es):

Erlang/OTP is a set of libraries for the Erlang programming language. Prior to versions OTP-27.3.1, 26.2.5.10, and 25.3.2.19, a maliciously formed KEX init message can result with high memory usage. Implementation does not verify RFC specified limits on algorithm names (64 characters) provided in KEX init message. Big KEX init packet may lead to inefficient processing of the error data. As a result, large amount of memory will be allocated for processing malicious data. Versions OTP-27.3.1, OTP-26.2.5.10, and OTP-25.3.2.19 fix the issue. Some workarounds are available. One may set option parallel_login to false and/or reduce the max_sessions option.(CVE-2025-30211)

Erlang is a general-purpose programming language and runtime environment. Erlang has built-in support for concurrency, distribution and fault tolerance. Erlang is used in several large telecommunication systems from Ericsson.

Security Fix(es):

Erlang/OTP is a set of libraries for the Erlang programming language. Prior to versions OTP-27.3.1, 26.2.5.10, and 25.3.2.19, a maliciously formed KEX init message can result with high memory usage. Implementation does not verify RFC specified limits on algorithm names (64 characters) provided in KEX init message. Big KEX init packet may lead to inefficient processing of the error data. As a result, large amount of memory will be allocated for processing malicious data. Versions OTP-27.3.1, OTP-26.2.5.10, and OTP-25.3.2.19 fix the issue. Some workarounds are available. One may set option parallel_login to false and/or reduce the max_sessions option.(CVE-2025-30211)

Erlang is a general-purpose programming language and runtime environment. Erlang has built-in support for concurrency, distribution and fault tolerance. Erlang is used in several large telecommunication systems from Ericsson.

Security Fix(es):

Erlang/OTP is a set of libraries for the Erlang programming language. Prior to versions OTP-27.3.1, 26.2.5.10, and 25.3.2.19, a maliciously formed KEX init message can result with high memory usage. Implementation does not verify RFC specified limits on algorithm names (64 characters) provided in KEX init message. Big KEX init packet may lead to inefficient processing of the error data. As a result, large amount of memory will be allocated for processing malicious data. Versions OTP-27.3.1, OTP-26.2.5.10, and OTP-25.3.2.19 fix the issue. Some workarounds are available. One may set option parallel_login to false and/or reduce the max_sessions option.(CVE-2025-30211)

Erlang is a general-purpose programming language and runtime environment. Erlang has built-in support for concurrency, distribution and fault tolerance. Erlang is used in several large telecommunication systems from Ericsson.

Security Fix(es):

Erlang/OTP is a set of libraries for the Erlang programming language. Prior to versions OTP-27.3.1, 26.2.5.10, and 25.3.2.19, a maliciously formed KEX init message can result with high memory usage. Implementation does not verify RFC specified limits on algorithm names (64 characters) provided in KEX init message. Big KEX init packet may lead to inefficient processing of the error data. As a result, large amount of memory will be allocated for processing malicious data. Versions OTP-27.3.1, OTP-26.2.5.10, and OTP-25.3.2.19 fix the issue. Some workarounds are available. One may set option parallel_login to false and/or reduce the max_sessions option.(CVE-2025-30211)

Erlang/OTP is a set of libraries for the Erlang programming language. Prior to versions OTP-27.3.1, 26.2.5.10, and 25.3.2.19, a maliciously formed KEX init message can result with high memory usage. Implementation does not verify RFC specified limits on algorithm names (64 characters) provided in KEX init message. Big KEX init packet may lead to inefficient processing of the error data. As a result, large amount of memory will be allocated for processing malicious data. Versions OTP-27.3.1, OTP-26.2.5.10, and OTP-25.3.2.19 fix the issue. Some workarounds are available. One may set option parallel_login to false and/or reduce the max_sessions option.

Erlang/OTP is a set of libraries for the Erlang programming language. Prior to versions OTP-27.3.1, 26.2.5.10, and 25.3.2.19, a maliciously formed KEX init message can result with high memory usage. Implementation does not verify RFC specified limits on algorithm names (64 characters) provided in KEX init message. Big KEX init packet may lead to inefficient processing of the error data. As a result, large amount of memory will be allocated for processing malicious data. Versions OTP-27.3.1, OTP-26.2.5.10, and OTP-25.3.2.19 fix the issue. Some workarounds are available. One may set option parallel_login to false and/or reduce the max_sessions option.

Erlang/OTP is a set of libraries for the Erlang programming language. Prior to versions OTP-27.3.1, 26.2.5.10, and 25.3.2.19, a maliciously formed KEX init message can result with high memory usage. Implementation does not verify RFC specified limits on algorithm names (64 characters) provided in KEX init message. Big KEX init packet may lead to inefficient processing of the error data. As a result, large amount of memory will be allocated for processing malicious data. Versions OTP-27.3.1, OTP-26.2.5.10, and OTP-25.3.2.19 fix the issue. Some workarounds are available. One may set option parallel_login to false and/or reduce the max_sessions option.

This update for erlang26 fixes the following issues:

• CVE-2025-30211: Fixed KEX init error results with excessive memory usage (bsc#1240390)
• CVE-2025-32433: Fixed unauthenticated remote code execution in Erlang/OTP SSH (bsc#1241300)

It was discovered that Erlang OTP's SSH module did not limit the size of certain data in initialization messages. An attacker could possibly use this issue to consume large amount of memory leading to 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…