CVE-2025-30211: Erlang OTP

High severity, CVSS 7.5. EPSS: 0.5% chance of exploitation in the next 30 days.

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.

Affected products

• Erlang OTP: before OTP-27.3.1 (fixed in OTP-27.3.1); before OTP-26.2.5.10 (fixed in OTP-26.2.5.10); before OTP-25.3.2.19 (fixed in OTP-25.3.2.19)

Published 2025-03-28. Last modified 2026-06-17.