CVE-2026-5300

CVE-2026-5300 is a critical authentication bypass vulnerability affecting CoolerControl/coolercontrold versions prior to 4.0.0, which permits unauthenticated attackers to view and modify sensitive data through direct HTTP requests. The vulnerability has been assigned a CVSS score of 9.1 (Critical) with a network-based attack vector requiring no user interaction or special privileges, indicating severe exploitability. The flaw enables attackers to achieve both high confidentiality and integrity impacts by circumventing authentication controls. While the Exploit Prediction Scoring System (EPSS) score is low at 0.00016, the vulnerability is currently listed on the Active Hot List, suggesting ongoing security community attention and potential threat activity. Organizations running affected CoolerControl versions should prioritize immediate patching to version 4.0.0 or later to prevent unauthorized access to and modification of sensitive system data.