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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-31786 Detail

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


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
http://www.openwall.com/lists/oss-security/2026/04/28/12 CVE Mailing List  Third Party Advisory 
http://xenbits.xen.org/xsa/advisory-485.html CVE Mailing List  Third Party Advisory 
https://git.kernel.org/stable/c/27fdbab4221b375de54bf91919798d88520c6e28 kernel.org Patch 
https://git.kernel.org/stable/c/4b4defd2fce3f966c25adabf46644a85558f1169 kernel.org Patch 
https://git.kernel.org/stable/c/52cecff98bda2c51eed1c6ce9d21c5d6268fb19d kernel.org Patch 
https://git.kernel.org/stable/c/5c5ff7c7bd15bb536f44b10b3fb5b8408f344d0a kernel.org Patch 
https://git.kernel.org/stable/c/8288d031a01dbacfde3fc643f7be3d23504de64d kernel.org Patch 
https://git.kernel.org/stable/c/d5f59216650c51e5e3fcb7517c825bc8047f60ef kernel.org Patch 
https://git.kernel.org/stable/c/e3af585e1728c917682b6a3de9a69b41fb9194d4 kernel.org Patch 
https://git.kernel.org/stable/c/f458ba102da97fafca106327086fc95f3fc764cb kernel.org Patch 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-787 Out-of-bounds Write cwe source acceptance level NIST  

Known Affected Software Configurations Switch to CPE 2.2

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Change History

5 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-31786
NVD Published Date:
04/30/2026
NVD Last Modified:
05/06/2026
Source:
kernel.org