VulnerabilityPublished 9 Mar 2026

CVE-2025-41759: MBS UBR-01 Mk II · Failing Open

Affects MBS UBR-01 Mk IISource CVE Database V5

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Not known to be exploited · CVSS 4.9 Medium : upgrade to 6.0.1.0 when convenient.

Data as of 29 Oct 2026, 19:04 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 27% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 6.0.1.0

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

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

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: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 9 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 29 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 UBR-01 Mk II and UBR-02 and UBR-LON to 6.0.1.0.

Affected software

Product	Affected	Fixed in
MBSUBR-01 Mk II	Affected <6.0.1.0	Fixed in 6.0.1.0
MBSUBR-02	Affected <6.0.1.0	Fixed in 6.0.1.0
MBSUBR-LON	Affected <6.0.1.0	Fixed in 6.0.1.0

AI-suggested

If you cannot patch yet, administrators should avoid using unsupported wildcard identifiers such as "*" or "all" to block networks on the MBS UBR-01 Mk II device. Instead, explicitly specify each network to be blocked using supported identifiers.
Implement strict administrative access controls and audit logging to monitor configuration changes on the device to detect potential misuse or misconfiguration attempts.
Conduct regular configuration reviews and network segmentation validation to ensure that intended network blocks are effectively enforced.
Use external network monitoring and intrusion detection systems to identify unauthorized network access that may result from this vulnerability.
Engage with the vendor MBS for updates on patches or firmware releases addressing this issue and plan timely deployment once available.
Train network administrators on the correct configuration procedures and the risks of relying on unsupported input values.
Consider deploying compensating controls such as firewall rules or network access control lists outside the device to enforce network segmentation robustly.

Description

An administrator may attempt to block all networks by specifying "\*" or "all" as the network identifier. However, these values are not supported and do not trigger any validation error. Instead, they are silently interpreted as network 0 which results in no networks being blocked at all.

Impact

The primary impact of this vulnerability is a confidentiality breach risk due to unintended network access. Organizations relying on the MBS UBR-01 Mk II to enforce network segmentation or block unauthorized networks may find that attempts to block all networks using common wildcard identifiers fail silently, leaving networks exposed. This can allow unauthorized users or attackers to access sensitive network segments that were assumed to be blocked, potentially leading to data leakage or reconnaissance opportunities. Since administrative privileges are required to exploit this issue, the risk is higher in environments where multiple administrators manage the device or where insider threats exist. The lack of integrity and availability impact means the device continues to operate normally, which may delay detection of the misconfiguration. Globally, organizations using this device in critical infrastructure, enterprise networks, or government environments could face increased exposure to network-based attacks or data breaches if this vulnerability is not addressed.

CWE-636Not Failing Securely (Failing Open) (opens in a new tab)
Class weaknessOWASP Top 10 A10:2025: Mishandling of Exceptional Conditions (opens in a new tab)
When the product encounters an error condition or failure, its design requires it to fall back to a state that is less secure than other options that are available, such as selecting the weakest encryption algorithm or using the most permissive access control restrictions.
Architecture and Design
Subdivide and allocate resources and components so that a failure in one part does not affect the entire product.
OWASP Cheat Sheets
Logging (opens in a new tab)
Error Handling (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

mbs-solutions.de/mbs-2025-0001 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 16 Mar 2026, 09:41 UTC

WeaknessesCWE-636

Technical details

References

Community reviews

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