CVE-2026-23354 x86/fred: Correct speculative safety in fred_extint()
A speculative execution flaw in the Linux kernel's FRED interrupt handler could allow attackers to leak sensitive memory contents via side-channel attacks.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-23354?
CVE-2026-23354 is a high-severity vulnerability in Linux kernel, published on 25 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
x86/fred: Correct speculative safety in fred_extint()
array_index_nospec() is no use if the result gets spilled to the stack, as it makes the believed safe-under-speculation value subject to memory predictions.
For all practical purposes, this means array_index_nospec() must be used in the expression that accesses the array.
As the code currently stands, it's the wrong side of irqentry_enter(), and 'index' is put into %ebp across the function call.
Remove the index variable and reposition array_index_nospec(), so it's calculated immediately before the array access.
Weakness: CWE-129
Which versions are affected by CVE-2026-23354?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-23354?
Apply the vendor's patch.
Is CVE-2026-23354 being exploited?
There is no known exploitation of CVE-2026-23354 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-23354, DEBIAN-CVE-2026-23354, GHSA-4jgp-jccm-6ppx, ROOT-OS-DEBIAN-13-CVE-2026-23354, UBUNTU-CVE-2026-23354.