CVE-2026-23133

What it actually does

The vulnerability is a mismatch in DMA buffer handling in the ath10k WiFi driver where dma_free_coherent() is called with aligned addresses instead of the original unaligned addresses stored during dma_alloc_coherent(), resulting in improper memory deallocation and potential memory corruption.

Why it matters to the business

Affected Ubuntu 20.04 systems using linux-aws-5.15 or linux-azure-5.15 kernels may experience kernel crashes or instability when the ath10k driver performs DMA operations, leading to service disruption until systems are updated; low EPSS and no KEV listing suggest limited immediate widespread risk.

How an attack unfolds

An attacker with local access interacts with the WiFi subsystem to trigger DMA buffer allocation and subsequent free paths in the ath10k driver, causing the driver to free incorrect addresses and corrupt kernel memory structures.

How to fix it

Upgrade linux-aws-5.15 packages to version 5.15.0-1044.49~20.04.1 or later and linux-azure-5.15 packages to version 5.15.0-1046.53~20.04.1 or later on Ubuntu 20.04 LTS systems.

How to confirm the fix worked

Confirm the running kernel version is at or above the listed fixed versions, review ath10k driver source for correct unaligned pointer usage in DMA free calls, and perform functional testing of WiFi DMA operations.

Typical attack path

1. Gain local user access on an affected system
2. Trigger ath10k DMA allocation via WiFi interface operations
3. Force the mismatched dma_free_coherent() call
4. Induce kernel memory corruption leading to denial of service

How to detect it

Search system logs for ath10k-related kernel oops, warnings about DMA addresses, or panics occurring during WiFi driver unload or buffer management.

What your security team should do

• Apply the specified kernel updates to all affected Ubuntu 20.04 instances without delay
• Restrict local access to systems with ath10k hardware until patched
• Monitor kernel logs for DMA-related warnings in ath10k