CVE-2019-19581: Fedoraproject Fedora

Medium severity, CVSS 6.5. EPSS: 0.4% chance of exploitation in the next 30 days.

An issue was discovered in Xen through 4.12.x allowing 32-bit Arm guest OS users to cause a denial of service (out-of-bounds access) because certain bit iteration is mishandled. In a number of places bitmaps are being used by the hypervisor to track certain state. Iteration over all bits involves functions which may misbehave in certain corner cases: On 32-bit Arm accesses to bitmaps with bit a count which is a multiple of 32, an out of bounds access may occur. A malicious guest may cause a hypervisor crash or hang, resulting in a Denial of Service (DoS). All versions of Xen are vulnerable. 32-bit Arm systems are vulnerable. 64-bit Arm systems are not vulnerable.

Affected products

• Fedoraproject Fedora: version 31 only
• Xen Xen: from 4.8.0, up to and including 4.12.1

Published 2019-12-11. Last modified 2026-06-17.