# CVE-2026-80724: linux: In the Linux kernel, the following vulnerability has been resolved:  ptp: vmclock: prevent read-only mappings from be...

CVE-2026-80724 is fixed in 20 products on 1 platform, first by DEBIAN-CVE-2026-80724, released September 4, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-80724
- Priority: High
- CVSS: 8.8 (high)
- EPSS: 0.0018
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Aug 28, 2026

## 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).

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | bpftool6.18 amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 |
| Linux | bpftool6.18-debuginfo amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 |
| Linux | kernel-livepatch-6.18.48-107.148 amzn 2023 | 1:1.0-0.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 |
| Linux | kernel6.18 amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 |
| Linux | kernel6.18-debuginfo amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 |
| Linux | kernel6.18-debuginfo-common-aarch64 amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 |
| Linux | kernel6.18-debuginfo-common-x86_64 amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 |
| Linux | kernel6.18-devel amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 |
| Linux | kernel6.18-headers amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 |
| Linux | kernel6.18-modules-extra amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 |
| Linux | kernel6.18-modules-extra-common amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 |
| Linux | kernel6.18-tools amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 |
| Linux | kernel6.18-tools-debuginfo amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 |
| Linux | kernel6.18-tools-devel amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 |
| Linux | linux Debian 14 | 7.1.12-1 | [DEBIAN-CVE-2026-80724](https://patchblox.com/security/data/fix/linux/debian-cve-2026-80724.md) | Sep 4, 2026 |
| Linux | microvm-kernel6.18 amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 |
| Linux | perf6.18 amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 |
| Linux | perf6.18-debuginfo amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 |
| Linux | python3-perf6.18 amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 |
| Linux | python3-perf6.18-debuginfo amzn 2023 | 1:6.18.48-107.148.amzn2023 | [ALAS2023-2026-3139](https://patchblox.com/security/data/fix/linux/alas2023-2026-3139.md) | Sep 28, 2026 |

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Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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