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

How to Fix CVE-2026-23353: Critical Vulnerability in Linux

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

*By Sai Kiran Pandrala*

⚡ At a glance
SeverityNot verified - see advisory
Actively exploited?Not currently listed in CISA KEV
Affected93f53db9f9dc4a16b40ecd18e6d338ad57e4b670 < 85c98b81849e4724ae99005a6cccd33cab9cfd18, 93f53db9f9dc4a16b40ecd18e6d338ad57e4b670 < a9c354e656597aededa027d63d2ff0973f6b033f, 6.19
Fixed in0, 6.19.7, 7.0
Type (CWE)Not verified

What is CVE-2026-23353?

CVE-2026-23353 is a security flaw in Linux. In the Linux kernel, the following vulnerability has been resolved: ice: fix crash in ethtool offline loopback test Since the conversion of ice to page pool, the ethtool loopback test crashes: BUG: kernel NULL pointer dereference, address: 000000000000000c #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 1100f1067 P4D 0 Oops: Oops: 0002 [#1] SMP NOPTI CPU: 23 UID: 0 PID: 5904 Comm: ethtool Kdump: loaded Not tainted 6.19.0-0.rc7.260128g1f97d9dcf5364.49.eln154.x86_64 #1 PREEMPT(lazy) Hardware name: [...] RIP: 0010:ice_alloc_rx_bufs+0x1cd/0x310 [ice] Code: 83 6c 24 30 01 66 41 89 47 08 0f 84 c0 00 00 00 41 0f b7 dc 48 8b 44 24 18 48 c1 e3 04 41 bb 00 10 00 00 48 8d 2c 18 8b 04 24 <89> 45 0c 41 8b 4d 00 49 d3 e3 44 3b 5c 24 24 0f 83 ac fe ff ff 44 RSP: 0018:ff7894738aa1f768 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000700 RDI: 0000000000000000 RBP: 0000000000000000 R08: ff16dcae79880200 R09: 0000000000000019 R10: 0000000000000001 R11: 0000000000001000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ff16dcae6c670000 FS: 00007fcf428850c0(0000) GS:ff16dcb149710000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000000000c CR3: 0000000121227005 CR4: 0000000000773ef0 PKRU: 55555554 Call Trace: <TASK> ice_vsi_cfg_rxq+0xca/0x460 [ice] ice_vsi_cfg_rxqs+0x54/0x70 [ice] ice_loopback_test+0xa9/0x520 [ice] ice_self_test+0x1b9/0x280 [ice] ethtool_self_test+0xe5/0x200 __dev_ethtool+0x1106/0x1a90 dev_ethtool+0xbe/0x1a0 dev_ioctl+0x258/0x4c0 sock_do_ioctl+0xe3/0x130 __x64_sys_ioctl+0xb9/0x100 do_syscall_64+0x7c/0x700 entry_SYSCALL_64_after_hwframe+0x76/0x7e [...] It crashes because we have not initialized libeth for the rx ring. Fix it by treating ICE_VSI_LB VSIs slightly more like normal PF VSIs and letting them have a q_vector.

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-2026-23353

  1. Read the vendor advisory in full: https://git.kernel.org/stable/c/85c98b81849e4724ae99005a6cccd33cab9cfd18
  2. Upgrade Linux to 0, 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: 6.19.7, 7.0
# Source advisory: https://git.kernel.org/stable/c/85c98b81849e4724ae99005a6cccd33cab9cfd18

# 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-2026-23353 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-2026-23353?

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.*