⚠ Reference material — not professional advice. Test in staging, back up first, verify against your specific version. Use your own judgment for your environment.
● High · CVSS 7.8

How to Fix CVE-2026-23336: Critical Vulnerability in Linux

Other vulnerabilities in the same area that are worth patching alongside this one:

*By Sai Kiran Pandrala*

⚡ At a glance
SeverityCVSS 7.8 - High
Actively exploited?Not currently listed in CISA KEV
Affected1f87f7d3a3b42b20f34cb03f0fd1a41c3d0e27f3 < 82a35356b5c1f75fe6a8a561db44e8d0e49da8f9, 1f87f7d3a3b42b20f34cb03f0fd1a41c3d0e27f3 < b2e9626a9d16b9bbbd06498c9e73c93be354dc7a, 1f87f7d3a3b42b20f34cb03f0fd1a41c3d0e27f3 < eeea8da43ab86ac0a6b9cec225eec91564346940, 1f87f7d3a3b42b20f34cb03f0fd1a41c3d0e27f3 < fa18639deab4a3662d543200c5bfc29bf4e23173, 1f87f7d3a3b42b20f34cb03f0fd1a41c3d0e27f3 < 57e39fe8da573435fa35975f414f4dc17d9f8449, 1f87f7d3a3b42b20f34cb03f0fd1a41c3d0e27f3 < 584279ad9ff1e8e7c5494b9fce286201f7d1f9e2, and others
Fixed in0, 5.10.253, 5.15.203, 6.1.167, 6.6.130, 6.12.77
Type (CWE)Not verified

What is CVE-2026-23336?

CVE-2026-23336 is a security flaw in Linux. In the Linux kernel, the following vulnerability has been resolved: wifi: cfg80211: cancel rfkill_block work in wiphy_unregister() There is a use-after-free error in cfg80211_shutdown_all_interfaces found by syzkaller: BUG: KASAN: use-after-free in cfg80211_shutdown_all_interfaces+0x213/0x220 Read of size 8 at addr ffff888112a78d98 by task kworker/0:5/5326 CPU: 0 UID: 0 PID: 5326 Comm: kworker/0:5 Not tainted 6.19.0-rc2 #2 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Workqueue: events cfg80211_rfkill_block_work Call Trace: <TASK> dump_stack_lvl+0x116/0x1f0 print_report+0xcd/0x630 kasan_report+0xe0/0x110 cfg80211_shutdown_all_interfaces+0x213/0x220 cfg80211_rfkill_block_work+0x1e/0x30 process_one_work+0x9cf/0x1b70 worker_thread+0x6c8/0xf10 kthread+0x3c5/0x780 ret_from_fork+0x56d/0x700 ret_from_fork_asm+0x1a/0x30 </TASK> The problem arises due to the rfkill_block work is not cancelled when wiphy is being unregistered. To fix the issue cancel the corresponding work in wiphy_unregister().

Why this CVE matters

Unpatched network-facing software is the leading initial-access vector in public breach reporting. Treat any CVSS-9 class flaw on an internet-reachable system as urgent, regardless of whether public exploit code has been observed yet.

For deployments of Linux that have been exposed to the public internet during the disclosure window, the operating assumption should be that scanning has already happened. Even where exploitation has not been publicly observed, scanning for the vulnerable fingerprint is cheap and routine. Patching closes the door; log review and credential rotation close out the rest of the response.

Am I affected?

You are affected if your installation matches any of these version ranges:

Check your installed version against the list above. If you cannot determine the version, treat the system as affected and follow the upgrade path below.

Run uname -r to read the kernel release. Compare against the affected ranges; on distro kernels, also check the package version with dpkg -l linux-image-$(uname -r) or rpm -q kernel.

How to fix CVE-2026-23336

  1. Read the vendor advisory in full: https://git.kernel.org/stable/c/82a35356b5c1f75fe6a8a561db44e8d0e49da8f9
  2. Upgrade Linux to 0, 5.10.253, 5.15.203, 6.1.167, 6.6.130, 6.12.77, 6.18.17, 6.19.7, 7.0 or a later version listed in the vendor advisory.
  3. Back up the configuration (and database, where applicable) before upgrading.
  4. Apply the patch in a maintenance window. For HA pairs, upgrade the standby node first, fail over, then upgrade the former primary.
  5. Restart the affected service so the patched binary loads, then verify the new version (see verification section).

Patch the Linux kernel


# Target fixed version: 5.10.253, 5.15.203, 6.1.167
# Source advisory: https://git.kernel.org/stable/c/82a35356b5c1f75fe6a8a561db44e8d0e49da8f9

# Confirm the running kernel.
uname -r

# Debian / Ubuntu - pull the security update.
sudo apt update
sudo apt install --only-upgrade linux-image-generic linux-headers-generic
sudo reboot

# RHEL / Rocky / AlmaLinux / Fedora.
sudo dnf upgrade --refresh kernel kernel-core kernel-modules -y
sudo reboot

# After reboot, confirm the new kernel is running and compare against the fixed version above.
uname -r
dpkg -l linux-image-$(uname -r) 2>/dev/null | tail -1
rpm -q kernel 2>/dev/null


# Container hosts: bump the host kernel via the same package manager,
# then restart container runtimes so workloads pick up the new host.
sudo systemctl restart docker
sudo systemctl restart containerd


# Windows admin workstation - verify Linux fleet kernels via Ansible (WinRM).
ansible linux -m shell -a "uname -r" -i inventory.ini

Verify the fix landed


# 1. Confirm the running version matches the fixed-in version listed above.
# 2. Re-scan with your vulnerability scanner (Nessus, Qualys, Tenable, OpenVAS).
#    The scanner should no longer flag this CVE on the patched target.
# 3. Inspect recent service / kernel logs for crash-loops or rollback events.
journalctl --since "10 minutes ago" | tail -50
dmesg --since "10 minutes ago" 2>/dev/null | tail -50

If you cannot patch immediately

No official workaround exists beyond restricting network exposure to the affected component. Apply the vendor patch as the primary remediation.

How to verify the fix worked

If your installation was internet-reachable during the disclosure window, treat log review as part of the remediation rather than an optional follow-up. Look for log entries that do not match your normal request patterns, especially repeated requests to the same uncommon endpoint, and any administrative changes you cannot tie back to a known operator.

Frequently asked questions

Is CVE-2026-23336 being exploited in the wild?

Public exploitation has not been confirmed by CISA at the time of writing. Treat the patch as time-sensitive anyway; reports often lag actual abuse.

Will a WAF or IDS rule fully mitigate CVE-2026-23336?

No. Network-layer filters can reduce noise and slow opportunistic scanners, but they will not stop a determined attacker. The vendor patch is the only durable fix.

How long should I plan for the upgrade?

Typical vendor-documented upgrade windows for Linux run from a few minutes to under an hour depending on cluster size. Test in a staging environment first and follow the vendor's documented HA upgrade order.

References

*This guide was assembled from the official vendor advisory, the NVD record, and the CISA KEV catalog entry on 2026-05-25. Always confirm against the vendor advisory before applying changes in production.*