Improper Null Termination The advisory has been revoked - it doesn't affect any version of package perf (opens in a new tab)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-RHEL10-PERF-16357826
- published4 May 2026
- disclosed30 Apr 2026
Introduced: 30 Apr 2026
CVE-2026-31786 (opens in a new tab)Amendment
The Red Hat security team deemed this advisory irrelevant for RHEL:10.
NVD Description
Note: Versions mentioned in the description apply only to the upstream perf package and not the perf package as distributed by RHEL.
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
References
- https://bugzilla.redhat.com/show_bug.cgi?id=2464096
- https://access.redhat.com/security/cve/CVE-2026-31786
- https://access.redhat.com/errata/RHSA-2026:27288
- https://git.kernel.org/stable/c/27fdbab4221b375de54bf91919798d88520c6e28
- https://git.kernel.org/stable/c/4b4defd2fce3f966c25adabf46644a85558f1169
- https://git.kernel.org/stable/c/52cecff98bda2c51eed1c6ce9d21c5d6268fb19d
- https://git.kernel.org/stable/c/5c5ff7c7bd15bb536f44b10b3fb5b8408f344d0a
- https://git.kernel.org/stable/c/8288d031a01dbacfde3fc643f7be3d23504de64d
- https://git.kernel.org/stable/c/d5f59216650c51e5e3fcb7517c825bc8047f60ef
- https://git.kernel.org/stable/c/e3af585e1728c917682b6a3de9a69b41fb9194d4
- https://git.kernel.org/stable/c/f458ba102da97fafca106327086fc95f3fc764cb
- http://www.openwall.com/lists/oss-security/2026/04/28/12
- http://xenbits.xen.org/xsa/advisory-485.html