CVE-2026-89687

nfsd: ensure nfsd_file_do_acquire() does not use a non-opened file

HIGH
7.5
CVSS Score
Published: September 11, 2026 at 07:46 PM UTC
Updated: October 19, 2026 at 09:18 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.5
Exploit prediction
EPSS 0.5%

Description

In the Linux kernel, the following vulnerability has been resolved: nfsd: ensure nfsd_file_do_acquire() does not use a non-opened file ->atomic_open is permitted to return success without actually opening the file. It indicates this by calling finish_no_open(). This means dentry_create() can return a file which hasn't been opened. This is extremely unlikely as ->atomic_open handlers typically use finish_no_open() only for already existing files, and dentry_create() isn't called in that case, and the parent being locked should prevent races. However out of an abundance of caution it seems wise to teach nfsd to only use the file returned by dentry_create() if FMODE_OPENED is set, indicating that it has in fact been opened.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

64a989dbd144e0622371396461b11335459692d27.0
Vendor states this is fixed in 5859cc01fee06a2cd7458905a9593082fbab06e1 (fixed)
Vendor states this is fixed in a95a1cffacd0203100297001719160160f443dd6 (fixed)
Vendor states this is fixed in 7.0 (unaffected)
Vendor states this is fixed in 7.2.4 (unaffected)
Vendor states this is fixed in 7.3 (unaffected)
Vendor states this is fixed in 7.3-rc1 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

CVSS

7.5HIGHLinux
Vector?

Quick Info

StatusRECEIVED

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