VulnerabilityPublished 7 Oct 2025Updated 3 Nov 2025

CVE-2025-53476: Denial of Service Vulnerability Exists

Source GCVE Database

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Authoritative record:CVE-2025-53476· Medium 5.3

Not known to be exploited · CVSS 5.3 Medium.

Data as of 29 Oct 2026, 23:56 UTC

CVSS 3.1 base score

5.3Medium

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

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

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

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: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
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: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 7 Oct 2025
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.

ghsa-pm3x-2fvm-pvp8

What to do

AI-suggested

Until a fix is available, consider limiting network exposure of the ModbusTCP service and monitoring for unusual connection patterns that may indicate exploitation attempts.

Description

A denial of service (DoS) vulnerability exists in the ModbusTCP server functionality of OpenPLC version v3 (commit a931181e8b81e36fadf7b74d5cba99b73c3f6d58). An attacker can exploit this by opening a specially crafted series of TCP connections, causing the server to stop processing subsequent Modbus requests.

Impact

The vulnerability leads to a denial of service condition, impacting the availability of the ModbusTCP server. There is no impact on confidentiality or integrity. The server stops processing new Modbus requests after the attack, potentially disrupting industrial control processes relying on OpenPLC.

Summary

CVE-2025-53476 describes a denial of service vulnerability in the ModbusTCP server component of OpenPLC v3 (commit a931181e8b81e36fadf7b74d5cba99b73c3f6d58). The flaw allows an unauthenticated remote attacker to disrupt the server's ability to handle further Modbus requests by establishing a sequence of crafted TCP connections. This results in a loss of availability of the ModbusTCP service on the affected OpenPLC instance.

CWE-775Missing Release of File Descriptor or Handle after Effective Lifetime (opens in a new tab)
Variant weakness
The product does not release a file descriptor or handle after its effective lifetime has ended, i.e., after the file descriptor/handle is no longer needed.
Operation · Architecture and Design · Resource Limitation
Use resource-limiting settings provided by the operating system or environment. For example, when managing system resources in POSIX, setrlimit() can be used to set limits for certain types of resources, and getrlimit() can determine how many resources are available.
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 29 Oct 2026, 23:56 UTC

WeaknessesCWE-775

Technical details

References

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