Linux Kernel Vulnerability Affecting Virtual Clock Management
CVE-2026-80724
Key Information:
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What is CVE-2026-80724?
A vulnerability in the Linux kernel's virtual clock management allows userspace to exploit read-only memory mappings. By mapping the shared vmclock ABI page as read-only, an attacker could subsequently elevate it to writable using mprotect(). This alteration poses a risk as it may corrupt critical host-written timekeeping data, including the sequence counter and UTC time. The issue arises since the function responsible for memory mapping retains a VM_MAYWRITE flag for read-only mappings, enabling the potential for data corruption. This vulnerability has been addressed to ensure that read-only paths correctly clear the flag, preventing such escalation.
Affected Version(s)
Linux 20503272422693d793b84f88bf23fe4e955d3a33 < 5b4f2bec7bea6c04084d720d731bedee7caf878d
Linux 20503272422693d793b84f88bf23fe4e955d3a33 < 3f5677d2f817355147337f0453174c7bb0f3b66a
Linux 20503272422693d793b84f88bf23fe4e955d3a33 < 2496e141827102d6af512950057d402a2cfb2bfc
Exploit Proof of Concept (PoC)
PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.