libssh2 userauth.c userauth_password integer overflow

[nixpkgs-security-tracker]

• CVE-2026-7598
• Nixpkgs security tracker issue
• affected package maintainers: cc @SuperSandro2000

Description

A security vulnerability has been detected in libssh2 up to 1.11.1. The impacted element is the function userauth_password of the file src/userauth.c. Such manipulation of the argument username_len/password_len leads to integer overflow. The attack may be launched remotely. The name of the patch is 256d04b60d80bf1190e96b0ad1e91b2174d744b1. A patch should be applied to remediate this issue.

References

• userauth.c: username_len bounds checking libssh2/libssh2#1858 (patch, issue-tracking)
• libssh2/libssh2@256d04b (patch)

7.3 HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:X/RL:O/RC:C

• CVSS version: 3.1
• Attack Vector (AV): Network (N)
• Attack Complexity (AC): Low (L)
• Privileges Required (PR): None (N)
• User Interaction (UI): None (N)
• Scope (S): Unchanged (U)
• Confidentiality (C): Low (L)
• Integrity (I): Low (L)
• Availability (A): Low (L)
• Exploit Code Maturity (E): Not Defined (X)
• Remediation Level (RL): Official Fix (O)
• Report Confidence (RC): Confirmed (C)

Affected packages

• libssh2 (1.11.1@nixos-25.11, 1.11.1@nixos-unstable)