Vulnary
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Critical· 9.8official fix available

CVE-2024-56645

A critical bug in the Linux kernel’s J1939 networking code could let attackers crash the system by causing a reference count underflow on network packets.

publishedDec 27, 2024
last modifiedAug 4, 2026
sourcesNVD
severity · cvss
9.8
critical · how bad it is
exploitation · epss
<1%
14th 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 Sep 3, 2026

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

01

Who is affected

Linux kernel users, especially those running kernel 6.13 or earlier, who use the J1939 CAN bus protocol.

02

Real-world impact

An attacker could trigger a denial‑of‑service by sending crafted J1939 packets that cause the kernel to crash, disrupting network services and potentially affecting embedded automotive systems.

03

Why this severity

The CVSS score of 9.8 reflects that the flaw is exploitable over the network, requires no privileges, and can compromise confidentiality, integrity, and availability.

04

What to do about it

official fix available
recommended steps
  1. 01Upgrade the Linux kernel to version 6.13 or later.
  2. 02Reboot the system to load the new kernel.

NVD-referenced vendor advisory

05

Timeline

  1. Dec 27, 2024 · Dec 27, 2024
    Published
    Disclosed and added to the National Vulnerability Database.
  2. Aug 4, 2026 · 2d ago
    Advisory updated
    The NVD record was last revised.
  3. Aug 4, 2026 · 1d 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 →