---
cve: "CVE-2026-80724"
severity: "LOW"
cvss: 3.1
epss: "4.3%"
vendor: "Linux"
kev: false
exploited: false
published: "2026-08-28 07:03:08"
tags: [cve, security, low]
source: tsecurity.de CVE-Dossier
exported: "2026-09-03T22:35:39+02:00"
---

# CVE-2026-80724

> 3.1 LOW

## Beschreibung

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).

## Patch verfügbar (OSV)

- Kernel ≥ 6.18.47
- Kernel ≥ 7.1.11
- Kernel ≥ 7.2.1

## Referenzen

- <https://git.kernel.org/stable/c/5b4f2bec7bea6c04084d720d731bedee7caf878d>
- <https://git.kernel.org/stable/c/2496e141827102d6af512950057d402a2cfb2bfc>
- <https://git.kernel.org/stable/c/2e596e7814ba38cdc129991058b6c254ed37cb11>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-80724) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_