Critical· 9.8official fix available

CVE-2025-39841

A critical flaw in the Linux kernel’s SCSI LPFC driver can cause a use‑after‑free, letting attackers crash the system or potentially run arbitrary code. The bug occurs when the kernel frees a buffer before clearing its pointer, creating a race condition. The issue has been fixed in recent kernel releases.

publishedSep 19, 2025

last modifiedJul 30, 2026

sourcesNVD

severity · cvss

9.8

critical · how bad it is

exploitation · epss

<1%

36th 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.

Who is affected

Linux kernel 6.17 and earlier, including Debian 11.0.

Real-world impact

An attacker could crash the system or potentially execute arbitrary code by exploiting the use‑after‑free.

Why this severity

The CVSS score of 9.8 reflects the vulnerability’s complete loss of confidentiality, integrity, and availability, and the fact that it can be exploited remotely with no authentication or user interaction.

What to do about it

official fix available

recommended steps

01Upgrade to Linux kernel 6.17 or later.
02Reboot the system to apply the update.

NVD-referenced vendor advisory

Timeline

Sep 19, 2025 · Sep 19, 2025
Published
Disclosed and added to the National Vulnerability Database.
Jul 30, 2026 · 6d ago
Advisory updated
The NVD record was last revised.
Jul 30, 2026 · 6d ago
Official fix available
A vendor patch or mitigation now exists — see the remediation steps above.

How it’s attacked

Attack vectorNetwork (remote)

Attack complexityLow

Privileges requiredNone

User interactionNone needed

ScopeUnchanged

Confidentiality impactHigh

Integrity impactHigh

Availability impactHigh

References & advisories

git.kernel.org/stable/c/367cb5ffd8a8a4c85d…patch
git.kernel.org/stable/c/55658c7501467ca9ef…patch
git.kernel.org/stable/c/897f64b01c1249ac73…patch
git.kernel.org/stable/c/95b63d15fce5c54a73…patch
git.kernel.org/stable/c/9dba9a45c348e8460d…patch
git.kernel.org/stable/c/ab34084f42ee06a902…patch
git.kernel.org/stable/c/baa39f6ad79d372a6c…patch
git.kernel.org/stable/c/d96cc9a1b57725930c…patch
lists.debian.org/debian-lts-announce/2025/10…mailing listthird party advisory
lists.debian.org/debian-lts-announce/2025/10…mailing listthird party advisory
cert-portal.siemens.com/productcert/html/ssa-032379…
cert-portal.siemens.com/productcert/html/ssa-089022…

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 →