SB20260727112 - Out-of-bounds read in Linux kernel char hw_random driver

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Main Vulnerability Database SB20260727112

SB20260727112 - Out-of-bounds read in Linux kernel char hw_random driver

Published: July 27, 2026

Security Bulletin ID SB20260727112
CSH Severity
High
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Information disclosure

Breakdown by Severity

High 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Out-of-bounds read (CVE-ID: CVE-2026-64456)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to disclose sensitive information.

The vulnerability exists due to an out-of-bounds read in the virtio-rng driver copy_data() function when processing device-reported used.len values from a virtio-rng backend. A remote attacker can provide a specially crafted length value to disclose sensitive information.

The issue can leak adjacent guest-kernel slab contents through the guest RNG and can also be observed directly via /dev/hwrng. No guest userspace interaction is required for the initial out-of-bounds read to occur.


Remediation

Install update from vendor's website.

References