How severe is CVE-2025-51986?

CVE-2025-51986 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2025-51986 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (23rd percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2025-51986?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2025-51986 have an EU (EUVD) identifier?

Yes. CVE-2025-51986 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-24936.

When was CVE-2025-51986 published?

CVE-2025-51986 was published on 2025-08-14 and last updated on 2026-06-17.

CVE-2025-51986

CVE-2025-51986 is a high-severity vulnerability with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-835.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 0% (23rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-24936
Weakness: CWE-835
Published: 2025-08-14
Last modified: 2026-06-17

Description

An issue was discovered in the demo/LINUXTCP implementation of cwalter-at freemodbus v.2018-09-12 allowing attackers to reach an infinite loop via a crafted length value for a packet.

Frequently asked questions

What is CVE-2025-51986?: An issue was discovered in the demo/LINUXTCP implementation of cwalter-at freemodbus v.2018-09-12 allowing attackers to reach an infinite loop via a crafted length value for a packet.
How severe is CVE-2025-51986?: CVE-2025-51986 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2025-51986 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (23rd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-51986?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-51986 have an EU (EUVD) identifier?: Yes. CVE-2025-51986 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-24936.
When was CVE-2025-51986 published?: CVE-2025-51986 was published on 2025-08-14 and last updated on 2026-06-17.

References

https://gist.github.com/jyjsunny/a9743a718ed3081b034c11201803f6b4

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