Main Vulnerability Database Vulnerabilities #VU146058

Improper access control in Linux kernel - CVE-2026-80724

Published: August 28, 2026 / Updated: August 31, 2026

Vulnerability identifier: #VU146058

CSH Severity: Low

CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-80724

CWE-ID: CWE-284

Exploitation vector: Local access

Exploit availability: Public exploit is available

Vulnerability details

The vulnerability allows a local user to modify host-written timekeeping data.

The vulnerability exists due to improper access control in vmclock_miscdev_mmap() when handling read-only mappings of the shared vmclock ABI page. A local user can map the page read-only and then change it to writable with mprotect() to modify host-written timekeeping data.

The corrupted data can include the sequence counter, UTC time, and TSC offset.

Affected software

Linux kernel

How to mitigate CVE-2026-80724

Install security update from vendor's repository.

Links to Public Exploits and PoC-codes

Exploit #12989 - cve-writeups-and-pocs (CVE-2026-80724 PoC + full write-up — Linux kernel ptp/vmclock read-only mapping becomes writable (VM_MAYWRITE). Discovered, reported & fixed by Abdifatah Suruur (suruurism)) (August 31, 2026)

External References

Related Security Bulletins

Improper access control in Linux kernel ptp driver