CVE-2026-80724
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.12%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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).
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- EPSS
- 0.12% probability · 2th percentile
- CISA KEV
- Not listed
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/0ce59c4148ecd1520c5592a63bb3c8991ee2d326
- https://git.kernel.org/stable/c/2496e141827102d6af512950057d402a2cfb2bfc
- https://git.kernel.org/stable/c/2e596e7814ba38cdc129991058b6c254ed37cb11
- https://git.kernel.org/stable/c/3f5677d2f817355147337f0453174c7bb0f3b66a
- https://git.kernel.org/stable/c/5b4f2bec7bea6c04084d720d731bedee7caf878d
- https://git.kernel.org/stable/c/a5edadbae57e2298a56cf7a4e774a027905a331f
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.