CVE-2026-31786
Description
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
How to fix
- linux linux_kernel5.10.254, 5.15.204, 6.1.170, 6.6.137, 6.12.85, 6.18.26, 7.0.3 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| linux linux_kernel | 4.13 ≤ v < 5.10.254, 5.11 ≤ v < 5.15.204, 5.16 ≤ v < 6.1.170, 6.2 ≤ v < 6.6.137, 6.7 ≤ v < 6.12.85, 6.13 ≤ v < 6.18.26, 6.19 ≤ v < 7.0.3, 7.1 | 5.10.254, 5.15.204, 6.1.170, 6.6.137, 6.12.85, 6.18.26, 7.0.3 |
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