CVE-2026-22321
Stack-Based Buffer Overflow in Telnet/SSH CLI Causes Session Crash
Publication date: 2026-03-18
Last updated on: 2026-03-18
Assigner: CERT VDE
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| phoenix_contact | fl_switch | to 3.53 (exc) |
| phoenix_contact | fl_switch | 3.53 |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-121 | A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability is a stack-based buffer overflow in the device's Telnet/SSH CLI login routine. It occurs when an unauthenticated attacker sends an oversized or unexpected username input. This overflow causes the thread handling the login attempt to crash, which forces the session to close.
How can this vulnerability impact me? :
The impact of this vulnerability is limited to a low-severity availability disruption. Specifically, the overflow condition crashes the login attempt thread and closes that session, but other CLI sessions remain unaffected.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
I don't know