CVE-2026-22321

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.

CVSS v3 5.3 MEDIUM

5.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://certvde.com/de/advisories/VDE-2025-104

Configurations

No configuration.

History

17 Jun 2026, 10:19

Type	Values Removed	Values Added
Summary		(es) Un desbordamiento de búfer basado en pila en la rutina de inicio de sesión CLI de Telnet/SSH del dispositivo ocurre cuando un atacante no autenticado envía una entrada de nombre de usuario sobredimensionada o inesperada. Una condición de desbordamiento bloquea el hilo que maneja el intento de inicio de sesión, forzando el cierre de la sesión. Debido a que otras sesiones CLI no se ven afectadas, el impacto se limita a una interrupción de disponibilidad de baja gravedad.

18 Mar 2026, 08:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-03-18 08:16

Updated : 2026-06-17 10:19

NVD link : CVE-2026-22321

Mitre link : CVE-2026-22321

CVE.ORG link : CVE-2026-22321

JSON object : View

Products Affected

No product.

CWE

CWE-121

Stack-based Buffer Overflow

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"semver"}], "defaultStatus": "unaffected"}, {"vendor": "Phoenix Contact", "product": "FL SWITCH 2303-8SP1", "versions": [{"status": "affected", "version": "0.0.0", "lessThan": "3.53", "versionType": "semver"}], "defaultStatus": "unaffected"}, {"vendor": "Phoenix Contact", "product": "FL NAT 2008", "versions": [{"status": "affected", "version": "0.0.0", "lessThan": "3.53", "versionType": "semver"}], "defaultStatus": "unaffected"}, {"vendor": "Phoenix Contact", "product": "FL NAT 2208", "versions": [{"status": "affected", "version": "0.0.0", "lessThan": "3.53", "versionType": "semver"}], "defaultStatus": "unaffected"}, {"vendor": "Phoenix Contact", "product": "FL NAT 2304-2GC-2SFP", "versions": [{"status": "affected", "version": "0.0.0", "lessThan": "3.53", "versionType": "semver"}], "defaultStatus": "unaffected"}, {"vendor": "Phoenix Contact", "product": "FL SWITCH 2008F", "versions": [{"status": "affected", "version": "0.0.0", "lessThan": "3.53", "versionType": "semver"}], "defaultStatus": "unaffected"}, {"vendor": "Phoenix Contact", "product": "FL SWITCH 2316/K1", "versions": [{"status": "affected", "version": "0.0.0", "lessThan": "3.53", "versionType": "semver"}], "defaultStatus": "unaffected"}, {"vendor": "Phoenix Contact", "product": "FL SWITCH 2506-2SFP/K1", "versions": [{"status": "affected", "version": "0.0.0", "lessThan": "3.53", "versionType": "semver"}], "defaultStatus": "unaffected"}, {"vendor": "Phoenix Contact", "product": "FL SWITCH 2508/K1", "versions": [{"status": "affected", "version": "0.0.0", "lessThan": "3.53", "versionType": "semver"}], "defaultStatus": "unaffected"}, {"vendor": "Phoenix Contact", "product": "FL SWITCH TSN 2316", "versions": [{"status": "affected", "version": "0.0.0", "lessThan": "3.53", "versionType": "semver"}], "defaultStatus": "unaffected"}, {"vendor": "Phoenix Contact", "product": "FL SWITCH TSN 2312-2GC-2SFP", "versions": [{"status": "affected", "version": "0.0.0", "lessThan": "3.53", "versionType": "semver"}], "defaultStatus": "unaffected"}, {"vendor": "Phoenix Contact", "product": "FL SWITCH TSN 2314-2SFP", "versions": [{"status": "affected", "version": "0.0.0", "lessThan": "3.53", "versionType": "semver"}], "defaultStatus": "unaffected"}, {"vendor": "Phoenix Contact", "product": "FL SWITCH 5924-4GC", "versions": [{"status": "affected", "version": "0.0.0", "lessThan": "3.53", "versionType": "semver"}], "defaultStatus": "unaffected"}, {"vendor": "Phoenix Contact", "product": "FL SWITCH 5916-8GC-4SFP+", "versions": [{"status": "affected", "version": "0.0.0", "lessThan": "3.53", "versionType": "semver"}], "defaultStatus": "unaffected"}, {"vendor": "Phoenix Contact", "product": "FL SWITCH 5924SFP-4GC", "versions": [{"status": "affected", "version": "0.0.0", "lessThan": "3.53", "versionType": "semver"}], "defaultStatus": "unaffected"}, {"vendor": "Phoenix Contact", "product": "FL SWITCH 5924-4SFP+", "versions": [{"status": "affected", "version": "0.0.0", "lessThan": "3.53", "versionType": "semver"}], "defaultStatus": "unaffected"}, {"vendor": "Phoenix Contact", "product": "FL SWITCH 5916SFP-8GC-4SFP+", "versions": [{"status": "affected", "version": "0.0.0", "lessThan": "3.53", "versionType": "semver"}], "defaultStatus": "unaffected"}]}], "published": "2026-03-18T08:16:29.527", "references": [{"url": "https://certvde.com/de/advisories/VDE-2025-104", "source": "info@cert.vde.com"}], "vulnStatus": "Awaiting Analysis", "weaknesses": [{"type": "Secondary", "source": "info@cert.vde.com", "description": [{"lang": "en", "value": "CWE-121"}]}], "descriptions": [{"lang": "en", "value": "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\u2011severity availability disruption."}, {"lang": "es", "value": "Un desbordamiento de b\u00fafer basado en pila en la rutina de inicio de sesi\u00f3n CLI de Telnet/SSH del dispositivo ocurre cuando un atacante no autenticado env\u00eda una entrada de nombre de usuario sobredimensionada o inesperada. Una condici\u00f3n de desbordamiento bloquea el hilo que maneja el intento de inicio de sesi\u00f3n, forzando el cierre de la sesi\u00f3n. Debido a que otras sesiones CLI no se ven afectadas, el impacto se limita a una interrupci\u00f3n de disponibilidad de baja gravedad."}], "lastModified": "2026-06-17T10:19:43.360", "sourceIdentifier": "info@cert.vde.com"}