Out-of-bounds Write Affecting kernel-rt-debug-kvm package, versions *


Severity

Recommended
0.0
medium
0
10

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.2% (10th percentile)

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  • Snyk IDSNYK-RHEL10-KERNELRTDEBUGKVM-21272629
  • published20 Oct 2026
  • disclosed18 Oct 2026

Introduced: 18 Oct 2026

NewCVE-2026-98568  (opens in a new tab)
CWE-787  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:10 kernel-rt-debug-kvm.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-rt-debug-kvm package and not the kernel-rt-debug-kvm package as distributed by RHEL. See How to fix? for RHEL:10 relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

vxlan: use one headroom snapshot for neighbour replies

vxlan_na_create() samples LL_RESERVED_SPACE() to size the reply skb and then samples it again to reserve headroom. A concurrent vxlan_changelink() can update needed_headroom between the two reads, creating a TOCTOU race. The second value can exceed the allocation and make the Ethernet header write out of bounds.

The race is reproducible on the unpatched kernel. It occurred when vxlan_na_create() generated a neighbour reply while vxlan_changelink() changed the link headroom. KASAN caught a four-byte write two bytes beyond a 704-byte skbuff_small_head allocation.

Snapshot the headroom once and use that value for both allocation and reservation.

CVSS Base Scores

version 3.1