CVE-2026-23354
kernel: x86/fred: Correct speculative safety in fred_extint()
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · March 25, 2026
Updated · June 28, 2026
Description
A flaw was found in the Linux kernel. This vulnerability affects the handling of speculative execution, a technique used by modern processors to improve performance. A protection mechanism intended to prevent information leakage can be bypassed when its result is temporarily stored in memory, making it vulnerable to memory prediction attacks. This could allow a local attacker to potentially gain access to sensitive information or circumvent security safeguards.
Statement
This flaw affects x86 systems using FRED (Flexible Return and Event Delivery) interrupt handling. The array_index_nospec() protection is ineffective when the sanitized value is spilled to stack before the array access, making it vulnerable to memory prediction attacks. FRED is a newer x86 feature not present on all systems, and exploiting this requires sophisticated speculative execution attacks.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 3.3CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
CWE-1037 · Processor Optimization Removal or Modification of Security-critical Code