Vulnary
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Critical· 9.8official fix available

CVE-2026-63800

A critical use‑after‑free bug was found in the Linux kernel’s pNFS layout handling. The flaw could let an attacker read or corrupt memory after a layout update. The issue has been fixed in a kernel update.

publishedJul 19, 2026
last modifiedJul 29, 2026
sourcesNVD
severity · cvss
9.8
critical · how bad it is
exploitation · epss
<1%
40th 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 19, 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 users running affected kernel versions that lack the pnfs_update_layout fix.

02

Real-world impact

An attacker could read or corrupt memory, potentially leading to arbitrary code execution or denial of service.

03

Why this severity

The CVSS score of 9.8 reflects that the vulnerability is exploitable over the network with no authentication, and it can compromise confidentiality, integrity, and availability.

04

What to do about it

official fix available
recommended steps
  1. 01Update your Linux kernel to a version that includes the pnfs_update_layout use‑after‑free fix.
  2. 02Reboot the system to load the new kernel.

NVD-referenced vendor advisory

05

Timeline

  1. Jul 19, 2026 · 11d ago
    Published
    Disclosed and added to the National Vulnerability Database.
  2. Jul 20, 2026 · 10d ago
    Official fix available
    A vendor patch or mitigation now exists — see the remediation steps above.
  3. Jul 29, 2026 · 17h ago
    Advisory updated
    The NVD record was last revised.
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 →