Vulnary
← back to the feed
Critical· 9.8official fix available

CVE-2025-40074

A critical vulnerability in the Linux kernel could allow attackers to execute arbitrary code or crash the system by exploiting a use‑after‑free condition in IPv4 handling. The flaw is triggered by network traffic and requires no authentication.

publishedOct 28, 2025
last modifiedJul 30, 2026
sourcesNVD
severity · cvss
9.8
critical · how bad it is
exploitation · epss
<1%
30th 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 29, 2026

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

01

Who is affected

Linux kernel (all versions prior to the fix).

02

Real-world impact

An attacker could gain full control of the affected system or cause a denial of service by sending specially crafted IPv4 packets.

03

Why this severity

The CVSS score of 9.8 reflects that the vulnerability is network‑based, requires no user interaction, and can lead to complete compromise of confidentiality, integrity, and availability.

04

What to do about it

official fix available
recommended steps
  1. 01Upgrade the Linux kernel to a version that includes the fix for CVE-2025-40074.

NVD-referenced vendor advisory

05

Timeline

  1. Oct 28, 2025 · Oct 28, 2025
    Published
    Disclosed and added to the National Vulnerability Database.
  2. Jul 30, 2026 · 6d ago
    Advisory updated
    The NVD record was last revised.
  3. Jul 30, 2026 · 6d 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 →