CVE-2026-22321 PUBLISHED

Stack-Based Buffer Overflow in CLI Login Username Handling over CLI

Assigner: CERTVDE
Reserved: 07.01.2026 Published: 18.03.2026 Updated: 18.03.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS Score: 5.3

Product Status

Vendor Phoenix Contact
Product FL SWITCH 2005
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2008
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2016
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2105
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2108
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2116
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2204-2TC-2SFX
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2205
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2206-2FX
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2206-2FX SM
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2206-2FX SM ST
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2206-2FX ST
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2206-2SFX
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2206-2SFX PN
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2206C-2FX
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2207-FX
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2207-FX SM
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2208
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2208 PN
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2208C
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2212-2TC-2SFX
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2214-2FX
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2214-2FX SM
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2214-2SFX
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2214-2SFX PN
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2216
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2216 PN
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2304-2GC-2SFP
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2306-2SFP
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2306-2SFP PN
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2308
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2308 PN
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2312-2GC-2SFP
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2314-2SFP
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2314-2SFP PN
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2316
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2316 PN
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2404-2TC-2SFX
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2406-2SFX
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2406-2SFX PN
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2408
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2408 PN
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2412-2TC-2SFX
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2414-2SFX
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2414-2SFX PN
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2416
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2416 PN
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2504-2GC-2SFP
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2506-2SFP
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2506-2SFP PN
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2508
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2508 PN
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2512-2GC-2SFP
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2514-2SFP
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2514-2SFP PN
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2516
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2516 PN
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2608
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2608 PN
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2708
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2708 PN
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2303-8SP1
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL NAT 2008
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL NAT 2208
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL NAT 2304-2GC-2SFP
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2008F
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2316/K1
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2506-2SFP/K1
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 2508/K1
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH TSN 2316
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH TSN 2312-2GC-2SFP
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH TSN 2314-2SFP
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 5924-4GC
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 5916-8GC-4SFP+
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 5924SFP-4GC
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 5924-4SFP+
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)
Vendor Phoenix Contact
Product FL SWITCH 5916SFP-8GC-4SFP+
Versions Default: unaffected
  • affected from 0.0.0 to 3.53 (excl.)

Credits

  • Gabriele Quagliarella from Nozomi Networks finder

References

Problem Types

  • CWE-121 Stack-based Buffer Overflow CWE