CVE-2026-22321 MEDIUM

CVE-2026-22321: Stack-Based Buffer Overflow in CLI Login Username Handling over CLI

Vendor Phoenix Contact
Product FL SWITCH 2005
Weakness CWE-121
Published March 18, 2026
Last update March 18, 2026
View on NVD All CVEs

CVSS base score

5.3/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

What the vulnerability does

01Description

A stack-based buffer overflow in the device's Telnet/SSH CLI login routine occurs when a unauthenticated attacker send an oversized or unexpected username input. An overflow condition crashes the thread handling the login attempt, forcing the session to close. Because other CLI sessions remain unaffected, the impact is limited to a low‑severity availability disruption.

Key dates

02Disclosure timeline

March 18, 2026 CVE published
March 18, 2026 Record updated