VulnerabilityPublished 18 Mar 2026

CVE-2026-22318: Phoenix Contact FL SWITCH 2005 · Stack-based Buffer Overflow

Affects Phoenix Contact FL SWITCH 2005Source CVE Database V5

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Not known to be exploited · CVSS 4.9 Medium : upgrade to 3.53 when convenient.

Data as of 31 Oct 2026, 08:20 UTC

CVSS 3.1 base score

4.9Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 28% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 3.53

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: High
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: High

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade FL to 3.53.

Affected software

Product	Affected	Fixed in
Phoenix ContactFL SWITCH 2005	Affected <3.53	Fixed in 3.53
Phoenix ContactFL SWITCH 2008	Affected <3.53	Fixed in 3.53
Phoenix ContactFL SWITCH 2016	Affected <3.53	Fixed in 3.53
Phoenix ContactFL SWITCH 2105	Affected <3.53	Fixed in 3.53
Phoenix ContactFL SWITCH 2108	Affected <3.53	Fixed in 3.53
Phoenix ContactFL SWITCH 2116	Affected <3.53	Fixed in 3.53

AI-suggested

Restrict network access to the management interfaces of FL SWITCH 2005 devices using network segmentation, firewalls, and access control lists to limit exposure to trusted administrators only.
Enforce strong authentication and credential management to prevent unauthorized privilege escalation that could enable exploitation.
Monitor device logs and network traffic for unusual POST requests or signs of memory corruption or process crashes.
5. Maintain an inventory of all Phoenix Contact FL SWITCH 2005 devices and prioritize patching or replacement as vendor fixes are released. 6. Employ network redundancy and failover mechanisms to minimize operational impact in case of device failure due to exploitation. 7. Conduct regular security assessments and penetration tests focusing on industrial control system components to identify and remediate similar vulnerabilities proactively.

Description

A stack-based buffer overflow vulnerability in the device's file transfer parameter workflow allows a high-privileged attacker to send oversized POST parameters, causing memory corruption in an internal process, resulting in a DoS attack.

Impact

The primary impact of this vulnerability is a denial-of-service condition on the Phoenix Contact FL SWITCH 2005 device, which can disrupt network connectivity and operations relying on this switch. For organizations, this can lead to temporary loss of network availability, affecting industrial control systems, automation processes, or critical infrastructure environments where these switches are deployed. Although the vulnerability does not allow data theft or manipulation, the resulting downtime can cause operational delays, safety risks, and financial losses. Since exploitation requires high privileges, the threat is mitigated somewhat by the need for prior access, but insider threats or lateral movement by attackers could leverage this flaw to cause disruption. The lack of known exploits reduces immediate risk, but the vulnerability remains a concern for organizations with these devices in their network, especially in sectors like manufacturing, energy, and critical infrastructure where Phoenix Contact products are common.

CWE-121Stack-based Buffer Overflow (opens in a new tab)
Variant weaknessLikelihood of exploit: HighCWE Top 25 (2025): #14
The product writes past the end of a buffer that was allocated on the stack.
Operation · Build and Compilation · Environment Hardening
Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index…
Architecture and Design
Use an abstraction library to abstract away risky APIs. Not a complete solution.
Implementation
Implement and perform bounds checking on input.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

certvde.com/de/advisories/VDE-2025-104 (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 18 Mar 2026, 07:59 UTC

WeaknessesCWE-121

Technical details

References

Community reviews

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