Vulnary
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Critical· 9.8official fix available

CVE-2026-23450

A critical bug in the Linux kernel’s SMC (Socket Message Control) handling can cause a crash when a listening socket is closed while a SYN packet is being processed. The flaw allows an attacker to trigger a null pointer dereference or use‑after‑free, leading to a denial of service. The issue has been fixed in recent kernel releases.

publishedApr 3, 2026
last modifiedJul 24, 2026
sourcesNVD
severity · cvss
9.8
critical · how bad it is
exploitation · epss
<1%
43th percentile · chance of exploitation in 30 days
(ai-assisted) A model wrote this summary from the official data, so double-check it against the source before you act on it. Read the official advisory →
auto-deletes from the system
counting…on Aug 25, 2026

An official fix is available, so this entry is kept for 30 days and then removed automatically.

01

Who is affected

Linux kernel, including version 7.0 and earlier. Any system running an affected kernel is vulnerable.

02

Real-world impact

An attacker could send specially crafted TCP packets to a vulnerable host, causing the kernel to crash and the system to reboot or become unresponsive. This would deny service to legitimate users.

03

Why this severity

The CVSS score of 9.8 reflects that the vulnerability can be exploited remotely over the network (AV:N), requires no user interaction (UI:N), and has no authentication (PR:N). It fully compromises confidentiality, integrity, and availability, giving an attacker the ability to crash the kernel.

04

What to do about it

official fix available
recommended steps
  1. 011. Check the current kernel version with `uname -r`.
  2. 022. Install the latest kernel update from your distribution’s package manager or from the kernel source.
  3. 033. Reboot the system to load the updated kernel.
  4. 044. Verify the new kernel version with `uname -r` to confirm the patch is applied.

NVD-referenced vendor advisory

05

Timeline

  1. Apr 3, 2026 · Apr 3, 2026
    Published
    Disclosed and added to the National Vulnerability Database.
  2. Jul 24, 2026 · 11d ago
    Advisory updated
    The NVD record was last revised.
  3. Jul 26, 2026 · 10d ago
    Official fix available
    A vendor patch or mitigation now exists — see the remediation steps above.
06

How it’s attacked

Attack vectorNetwork (remote)
Attack complexityLow
Privileges requiredNone
User interactionNone needed
ScopeUnchanged
Confidentiality impactHigh
Integrity impactHigh
Availability impactHigh
07

References & advisories

NVD advisory ↗Search advisories ↗
(ai-assisted) A model wrote this summary from the official data, so double-check it against the source before you act on it. Read the official advisory →