Vulnary
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Critical· 9.8official fix available

CVE-2026-43501

A critical bug in the Linux kernel’s IPv6 source routing handling can corrupt memory and allow attackers to execute arbitrary code. The flaw occurs when recompressing a Source Routing Header that becomes larger than the original, causing an out‑of‑bounds write. The issue has been fixed in recent kernel releases.

publishedMay 21, 2026
last modifiedJul 23, 2026
sourcesNVD
severity · cvss
9.8
critical · how bad it is
exploitation · epss
<1%
45th 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 24, 2026

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

01

Who is affected

All Linux kernel users running versions before the patch, including the 7.1 release and earlier. System administrators and users of Linux servers or devices that use raw IPv6 sockets are typical affected parties.

02

Real-world impact

An attacker could send a specially crafted IPv6 packet to a vulnerable system, corrupting kernel memory and potentially taking full control of the machine or causing a denial of service.

03

Why this severity

The CVSS score of 9.8 reflects that the vulnerability is exploitable over the network without authentication, requires no user interaction, and can compromise confidentiality, integrity, and availability of the system.

04

What to do about it

official fix available
recommended steps
  1. 011. Update the Linux kernel to the latest available version that includes the patch for CVE-2026-43501.
  2. 022. Reboot the system to load the updated kernel.

NVD-referenced vendor advisory

05

Timeline

  1. May 21, 2026 · May 21, 2026
    Published
    Disclosed and added to the National Vulnerability Database.
  2. Jul 23, 2026 · 12d ago
    Advisory updated
    The NVD record was last revised.
  3. Jul 25, 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 →