CVE-2026-21373

CVE-2026-21373 is a memory corruption vulnerability in IOCTL processing that occurs when accessing an output buffer without proper size validation. The flaw allows local attackers with limited privileges to trigger memory corruption during buffer operations. The vulnerability carries a HIGH severity rating (CVSS 7.8) due to its local attack vector, low complexity, and significant impact potential. An authenticated local user can exploit this without user interaction to achieve high-impact consequences including confidentiality breach, integrity compromise, and denial of service. Currently, there is no evidence of active exploitation in the wild, and the vulnerability is not listed on the CISA Known Exploited Vulnerabilities catalog. The EPSS score of 0.00013 indicates minimal real-world exploitation probability to date, and community attention remains low with the vulnerability classified as inactive on public tracking lists.