What is the CVSS score of CVE-2025-63651?

CVE-2025-63651 has a CVSS 3.1 base score of 7.5 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. EPSS exploitation probability: 0.9%.

Which versions of Monkey are affected by CVE-2025-63651?

A critical vulnerability in Monkey web server (CVE-2025-63651) allows remote attackers to crash the service through specially crafted HTTP requests, resulting in denial of service.

Is there a public PoC exploit available for CVE-2025-63651?

Yes, a public proof-of-concept exploit is available for CVE-2025-63651. Prioritise patching immediately. EPSS: 0.9%.

How to fix or mitigate CVE-2025-63651?

Within 24 hours: Identify and inventory all systems running Monkey web server and assess exposure to untrusted networks. Within 7 days: Implement network-level protections (WAF rules blocking malformed requests, rate limiting, network segmentation) and prepare contingency failover plans. Within 30 days: Monitor vendor security advisories for patch availability and plan immediate deployment; consider migrating to alternative web servers if patches remain unavailable.

Monkey CVE-2025-63651

HIGH

Use After Free (CWE-416)

2026-01-29 cve@mitre.org

Use After Free Denial Of Service Monkey

7.5

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

7.5 HIGH

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 22:00 vuln.today

PoC Detected

Feb 19, 2026 - 20:38 vuln.today

Public exploit code

CVE Published

Jan 29, 2026 - 20:16 nvd

HIGH 7.5

DescriptionCVE.org

A use-after-free in the mk_string_char_search function (mk_core/mk_string.c) of monkey commit f37e984 allows attackers to cause a Denial of Service (DoS) via sending a crafted HTTP request to the server.

AnalysisAI

Technical ContextAI

Classified as CWE-416 (Use After Free). Affects the mk_string_char_search component of Monkey. A use-after-free in the mk_string_char_search function (mk_core/mk_string.c) of monkey commit f37e984 allows attackers to cause a Denial of Service (DoS) via sending a crafted HTTP request to the server.

RemediationAI

Monitor vendor advisories for a patch. Restrict network access to the affected service where possible.

CVE-2025-63651 vulnerability details – vuln.today

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Monkey CVE-2025-63651

Severity by source

CVSS VectorNVD

Lifecycle Timeline

DescriptionCVE.org

AnalysisAI

Technical ContextAI

RemediationAI

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External POC / Exploit Code