Out-of-bounds Write Affecting kernel-debug-core package, versions <0:4.18.0-553.134.1.el8_10


Severity

Recommended
high

Based on Oracle Linux security rating.

Threat Intelligence

EPSS
0.2% (10th percentile)

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  • Snyk IDSNYK-ORACLE8-KERNELDEBUGCORE-17375271
  • published18 Jun 2026
  • disclosed30 Apr 2026

Introduced: 30 Apr 2026

CVE-2026-31786  (opens in a new tab)
CWE-787  (opens in a new tab)

How to fix?

Upgrade Oracle:8 kernel-debug-core to version 0:4.18.0-553.134.1.el8_10 or higher.
This issue was patched in ELSA-2026-26427.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-debug-core package and not the kernel-debug-core package as distributed by Oracle. See How to fix? for Oracle:8 relevant fixed versions and status.

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

CVSS Base Scores

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