Cloudanix VulnDB

CVE-2026-23444

High · 7.8

CVSS

7.8

EPSS

0.1%

Published

Apr 3, 2026

CISA due date

—

Cloudanix analysis

Monitor only SSVC: Track

A bug in Linux Wi-Fi code can let someone with access to the computer corrupt memory and potentially seize control of the machine.

Exploitation
Local Privilege
Attacker needs
Low Privilege
Complexity
Theoretical
Impact
Full Compromise
Component
OS kernel
Class
Memory Corruption
Remediation
Upgrade
Effort
Medium
Patch risk
Low

What it actually does

Inconsistent skb handling in ieee80211_tx_prepare_skb() leaves one error path (TX_DROP from ieee80211_tx_prepare) without kfree_skb while other paths free it; callers then perform their own frees, enabling double-free or use-after-free memory corruption in mac80211 Wi-Fi transmit paths.

Why it matters to the business

Local attackers can crash systems or escalate privileges on any Linux device using Wi-Fi, increasing downtime and risk of full host compromise in servers, laptops, and embedded devices; the issue affects the entire kernel ecosystem with no downstream fixed versions listed yet.

How an attack unfolds

An attacker with local access crafts network traffic or uses a malicious user-space program to force ieee80211_tx_prepare_skb into the TX_DROP error path, then leverages the resulting double-free or dangling skb pointer for memory corruption and code execution.

How to fix it

Upgrade the Linux kernel to a version containing the fix that adds kfree_skb to the first error path and removes redundant frees from ath9k, mt76, and mac80211_hwsim; apply the patch referenced in the commit that documents skb ownership in the function kdoc.

How to confirm the fix worked

Confirm the fix by inspecting the ieee80211_tx_prepare_skb function for a kfree_skb call on the TX_DROP path and verifying that callers no longer contain skb frees; test by forcing the error paths and checking for absence of double-free warnings or leaks.

Typical attack path

  1. Obtain local access on a Linux system with Wi-Fi enabled
  2. Trigger ieee80211_tx_prepare_skb failure through crafted 802.11 frames or API calls
  3. Exploit resulting double-free or use-after-free to corrupt kernel memory
  4. Escalate to root or execute arbitrary code

How to detect it

Search kernel logs and crash dumps for double-free warnings or skb-related oops in mac80211 or wireless drivers; examine audit logs for unusual local processes interacting with 80211 tx paths around the time of crashes.

What your security team should do

  • Prioritize kernel upgrades on all Wi-Fi enabled Linux hosts within the next 30 days
  • Monitor for new stable kernel releases that include this mac80211 change
  • Restrict local access via least-privilege policies until patches are deployed
  • Review wireless driver code for similar skb ownership issues

The record

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: always free skb on ieee80211_tx_prepare_skb() failure ieee80211_tx_prepare_skb() has three error paths, but only two of them free the skb. The first error path (ieee80211_tx_prepare() returning TX_DROP) does not free it, while invoke_tx_handlers() failure and the fragmentation check both do. Add kfree_skb() to the first error path so all three are consistent, and remove the now-redundant frees in callers (ath9k, mt76, mac80211_hwsim) to avoid double-free. Document the skb ownership guarantee in the function's kdoc.

Affected packages

Ecosystem Package Introduced Fixed

Related vulnerabilities