CVE-2026-89687
nfsd: ensure nfsd_file_do_acquire() does not use a non-opened file
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.
INFO
Published Date :
Sept. 11, 2026, 8:19 p.m.
Last Modified :
Sept. 11, 2026, 8:19 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-89687
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Apply the Linux kernel update.
- Verify FMODE_OPENED flag usage.
- Ensure files are opened correctly.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-89687.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/5859cc01fee06a2cd7458905a9593082fbab06e1 | |
| https://git.kernel.org/stable/c/a95a1cffacd0203100297001719160160f443dd6 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-89687 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-89687
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-89687 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-89687 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 11, 2026
Action Type Old Value New Value Added 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. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/89xxx/CVE-2026-89687.json">CVE-2026-89687</a> Added Reference https://git.kernel.org/stable/c/5859cc01fee06a2cd7458905a9593082fbab06e1 Added Reference https://git.kernel.org/stable/c/a95a1cffacd0203100297001719160160f443dd6