virtio-win Unmap Param Validation Buffer Overrun DoS vulnerability
CVE-2026-5164 Published on March 30, 2026
Virtio-win: virtio-win: denial of service via unvalidated descriptor count in unmap request
A flaw was found in virtio-win. The `RhelDoUnMap()` function does not properly validate the number of descriptors provided by a user during an unmap request. A local user could exploit this input validation vulnerability by supplying an excessive number of descriptors, leading to a buffer overrun. This can cause a system crash, resulting in a Denial of Service (DoS).
Vulnerability Analysis
CVE-2026-5164 is exploitable with local system access, and requires user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to be very high.
Timeline
Reported to Red Hat.
Made public.
Weakness Type
What is a Classic Buffer Overflow Vulnerability?
The program copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. A buffer overflow condition exists when a program attempts to put more data in a buffer than it can hold, or when a program attempts to put data in a memory area outside of the boundaries of a buffer. The simplest type of error, and the most common cause of buffer overflows, is the "classic" case in which the program copies the buffer without restricting how much is copied. Other variants exist, but the existence of a classic overflow strongly suggests that the programmer is not considering even the most basic of security protections.
CVE-2026-5164 has been classified to as a Classic Buffer Overflow vulnerability or weakness.
Products Associated with CVE-2026-5164
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