Out-of-bounds read in Linux kernel - CVE-2026-64121
Published: July 20, 2026
Vulnerability identifier: #VU138520
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-64121
CWE-ID: CWE-125
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to disclose sensitive information.
The vulnerability exists due to an out-of-bounds read in ifb_get_ethtool_stats in the IFB network driver when handling ethtool statistics requests on a device with more RX queues than TX queues. A local user can request ethtool statistics for a crafted asymmetric IFB device to disclose sensitive information.
Exploitation requires an IFB device configuration where the RX queue count exceeds the TX queue count.
How to mitigate CVE-2026-64121
Install security update from vendor's repository.
Sources
- https://git.kernel.org/stable/c/16bd798cb6d8337d7c3eea1adc412f31b5181d5b
- https://git.kernel.org/stable/c/2638e1773904d7aa8f24c6e7fda2ed7d69df6fa4
- https://git.kernel.org/stable/c/301a554e458e2f5ec47f2c336a7cb03b877f9fd6
- https://git.kernel.org/stable/c/5db89c99566fc4728cc92e941d8e1975711e24b5
- https://git.kernel.org/stable/c/6afdb8113cb007f9332f59a9b7fd45731b8a9de5
- https://git.kernel.org/stable/c/f8a5a76b4a683043c6eff2a060bcaa17f9316ad5