CVE-2026-80724: Linux

High severity, CVSS 8.8. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: ptp: vmclock: prevent read-only mappings from becoming writable vmclock_miscdev_mmap() rejects writable mappings of the shared vmclock ABI page with -EROFS, but leaves VM_MAYWRITE set. Userspace can map the page read-only and then upgrade it to writable with mprotect(), after which the guest can corrupt the host-written timekeeping data (sequence counter, UTC time, TSC offset) that the vmclock ABI defines as read-only. Clear VM_MAYWRITE on the read-only path so the mapping cannot be upgraded, as i915 does for its read-only objects and as fixed in drm/vc4 (CVE-2026-68445) and drm/panthor (CVE-2024-53071).

Affected products

• Linux Linux: from 6.13, before 6.18.47 (fixed in 6.18.47); from 6.19, before 7.1.11 (fixed in 7.1.11); from 7.2, before 7.2.1 (fixed in 7.2.1)

Published 2026-08-28. Last modified 2026-09-07.