CVE-2026-7598

Red Hat statement

To exploit this flaw, an attacker needs to be able to supply an excessively large value to the arguments of the `userauth_password` function, typically to an application processing untrusted SSH authentication requests. The primary security impact of this issue is a crash to the application linked to the library due to memory corruption, potentially allowing arbitrary code execution. Default Red Hat Enterprise Linux security features, including SELinux enforcement, Address Space Layout Randomization (ASLR) and NX (No-Execute) stack protection, significantly increase the difficulty of achieving arbitrary code execution, limiting the impact of this vulnerability. Due to these reasons, this vulnerability has been rated with an important severity.

Red Hat mitigation

To mitigate this flaw, applications linked to the libssh2 library should be configured or updated to exclusively use public key authentication. Explicitly disabling password-based logins prevents the application from executing the vulnerable userauth_password function.