CVEvulnerability

CVE-2026-31786

7.8 HIGH Published 2026-04-30 Modified 2026-10-19 Official page ↗
Status
Modified
Published
2026-04-30
Last modified
2026-10-19
Assigner
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS 3.1 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)
7.8 HIGH — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weaknesses
CWE-120, CWE-787

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

Affected configurations

• 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 (>= 6.2 < 6.6.137) • linux linux kernel (>= 6.7 < 6.12.85) • linux linux kernel (>= 6.13 < 6.18.26) • linux linux kernel (>= 6.19 < 7.0.3) • linux linux kernel 7.1

Related

Weakness · CWE (2)

  • CWE-120 Buffer Copy without Checking Size of Input weakness
  • CWE-787 Out-of-bounds Write weakness

References