Vulnary
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Critical· 9.8official fix available

CVE-2026-89542

A flaw in the Linux kernel’s SUNRPC GSS‑KRB5 unwrapping routine allows attackers to supply a malformed token that can cause out‑of‑bounds reads, integer underflows, and potentially arbitrary code execution. The issue has been fixed in a kernel patch.

publishedSep 11, 2026
last modifiedSep 13, 2026
sourcesNVD
severity · cvss
9.8
critical · how bad it is
exploitation · epss
<1%
6th 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 Oct 13, 2026

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

01

Who is affected

All Linux systems running kernel versions that contain the vulnerable SUNRPC GSS‑KRB5 unwrapping code – the exact affected releases are not listed in the source.

02

Real-world impact

An attacker who can send a crafted RPC request to a vulnerable system could execute arbitrary code with kernel privileges, potentially taking full control of the machine.

03

Why this severity

The CVSS score of 9.8 reflects that the vulnerability is exploitable remotely (AV:N), requires no user interaction (UI:N), and has no authentication or privilege requirements (PR:N). It allows complete compromise of confidentiality, integrity, and availability (C:H/I:H/A:H).

04

What to do about it

official fix available
recommended steps
  1. 01Update the Linux kernel to a version that includes the fix.

NVD description indicates the vulnerability has been resolved.

05

Timeline

  1. Sep 11, 2026 · 2d ago
    Published
    Disclosed and added to the National Vulnerability Database.
  2. Sep 13, 2026 · 7h 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 →
CVE-2026-89542: A flaw in the Linux kernel’s SUNRPC GSS‑KRB5 unwrapping routine allows · Vulnary