Out-of-bounds write in Linux kernel - CVE-2026-64304

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Main Vulnerability Database Vulnerabilities #VU139674

Out-of-bounds write in Linux kernel - CVE-2026-64304

Published: July 27, 2026


Vulnerability identifier: #VU139674
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-64304
CWE-ID: CWE-787
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to cause memory corruption.

The vulnerability exists due to an out-of-bounds write in qat_rsa_setkey_crt() when processing RSA CRT key components larger than half of the key size. A local user can provide a crafted RSA CRT key to cause memory corruption.

The issue occurs because CRT components are bounded by the modulus size in the generic RSA key parser, while the QAT driver allocates half-size DMA buffers for those components.


Affected software

Linux kernel
Red Hat Enterprise Linux Server - AUS
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux for ARM 64 - Extended Update Support
Red Hat Enterprise Linux for x86_64
Red Hat CodeReady Linux Builder for ARM 64 - Extended Update Support
Red Hat CodeReady Linux Builder for IBM z Systems - Extended Update Support
Red Hat CodeReady Linux Builder for Power, little endian - Extended Update Support
Red Hat CodeReady Linux Builder for x86_64 - Extended Update Support
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for IBM z Systems
openEuler
Ubuntu
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-devel
kernel-headers
kernel-source
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
python3-perf
python3-perf-debuginfo
kernel
kernel (Red Hat package)
kernel-extra-modules
linux (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

How to mitigate CVE-2026-64304

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
bpftool - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
bpftool-debuginfo - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
kernel-debuginfo - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
kernel-debugsource - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
kernel-devel - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
kernel-headers - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
kernel-source - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
kernel-tools - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
kernel-tools-debuginfo - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
kernel-tools-devel - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
perf - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
perf-debuginfo - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
python3-perf - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
python3-perf-debuginfo - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
kernel - addressed in versions 5.10.0-329.0.0.230, 6.6.0-145.3.29.160
kernel (Red Hat package) - addressed in versions 5.14.0-427.149.1.el9_4, 5.14.0-570.138.1.el9_6, 6.12.0-55.103.1.el10_0, 6.12.0-211.50.1.el10_2
kernel-extra-modules - update to 6.6.0-145.3.29.160
linux (Ubuntu package) - addressed in versions 7.0.0-31.31, 7.0.0-31.31.1, 7.0.0-31.31~24.04.1, 7.0.0-1006.7, 7.0.0-1011.11~24.04.1, 7.0.0-1012.12, 7.0.0-1012.12~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1013.13

External References

Related Security Bulletins