IT

Tracker / CVE-2026-31786

CVE-2026-31786

High 7.8

In the Linux kernel, the following vulnerability has been resolved: Buffer overflow in drivers/xen/sys-hypervisor.c The build id returned by HYPERVISOR_xen_version(XENVER_build_id) is neither NUL terminated nor a string. The first causes a buffer overflow as sprintf in buildid_show will read and copy till it finds a NUL. 00000000 f4 91 51 f4 dd 38 9e 9d 65 47 52 eb 10 71 db 50 |..Q..8..eGR..q.P| 00000010 b9 a8 01 42 6f 2e 32 |...Bo.2| 00000017 So use a memcpy instead of sprintf to have the correct value: 00000000 f4 91 51 f4 dd 00 9e 9d 65 47 52 eb 10 71 db 50 |..Q.....eGR..q.P| 00000010 b9 a8 01 42 |...B| 00000014 (the above have a hack to embed a zero inside and check it's returned correctly). This is XSA-485 / CVE-2026-31786

Affected products and versions

linux linux_kernel
linux linux_kernel · 4.13 → 5.10.254
linux linux_kernel · 5.11 → 5.15.204
linux linux_kernel · 5.16 → 6.1.170
linux linux_kernel · 6.13 → 6.18.26
linux linux_kernel · 6.19 → 7.0.3
linux linux_kernel · 6.2 → 6.6.137
linux linux_kernel · 6.7 → 6.12.85

Analysis

This page is not indexable yet.Until it carries original analysis — what it actually exposes, how to check in two minutes whether a system was touched, what to do if it was — the page stays noindex. The database decides that, not the template.

References