CVE-2026-53395
nfsd: fix dead ACL conflict guard in nfsd4_create
Description
In the Linux kernel, the following vulnerability has been resolved: nfsd: fix dead ACL conflict guard in nfsd4_create nfsd4_create() steals create->cr_dpacl/cr_pacl into the local nfsd_attrs via the designated initializer, then immediately sets the source pointers to NULL. The subsequent conflict guard tests the already-nilled source fields, making it permanently dead code: if (create->cr_acl) { if (create->cr_dpacl || create->cr_pacl) /* always false */ When a client encodes both FATTR4_WORD0_ACL and FATTR4_WORD2_POSIX_{DEFAULT,ACCESS}_ACL in the same CREATE fattr bitmap, nfsd4_acl_to_attr() overwrites attrs.na_pacl/na_dpacl without releasing the originals, leaking two posix_acl slab objects per request. Repeated requests cause unbounded slab exhaustion. Fix by checking attrs.na_dpacl/na_pacl (the stolen values) instead of the nilled create->cr_dpacl/cr_pacl, matching the correct pattern already used in nfsd4_setattr().
INFO
Published Date :
July 19, 2026, 12:16 p.m.
Last Modified :
Aug. 17, 2026, 5:17 a.m.
Remotely Exploit :
Yes !
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Update the Linux kernel to the resolved version.
- Ensure ACL conflict guards use correct field references.
- Verify proper memory management for ACL objects.
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-2026-53395.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/8371cc5c0a2cc2a71b3dcfd47ff1f7fcfc526a5e | Patch |
| https://git.kernel.org/stable/c/a60f25a800846ab8e5a13f8a9d05111f2aee55a7 | Patch |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-53395 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-2026-53395
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-2026-53395 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-53395 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.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 17, 2026
Action Type Old Value New Value Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'd2ca50606f5f0235d7780c1cd73b6614a5d07620', 'lessThan': '8371cc5c0a2cc2a71b3dcfd47ff1f7fcfc526a5e', 'versionType': 'git'}, {'status': 'affected', 'version': 'd2ca50606f5f0235d7780c1cd73b6614a5d07620', 'lessThan': 'a60f25a800846ab8e5a13f8a9d05111f2aee55a7', 'versionType': 'git'}], 'programFiles': ['fs/nfsd/nfs4proc.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '7.0'}, {'status': 'unaffected', 'version': '0', 'lessThan': '7.0', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '7.1.3', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['fs/nfsd/nfs4proc.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'd2ca50606f5f0235d7780c1cd73b6614a5d07620', 'lessThan': '8371cc5c0a2cc2a71b3dcfd47ff1f7fcfc526a5e', 'versionType': 'git'}, {'status': 'affected', 'version': 'd2ca50606f5f0235d7780c1cd73b6614a5d07620', 'lessThan': 'a60f25a800846ab8e5a13f8a9d05111f2aee55a7', 'versionType': 'git'}], 'programFiles': ['fs/nfsd/nfs4proc.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '7.0'}, {'status': 'unaffected', 'version': '0', 'lessThan': '7.0', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '7.1.3', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['fs/nfsd/nfs4proc.c'], 'defaultStatus': 'affected'}] -
Initial Analysis by [email protected]
Jul. 29, 2026
Action Type Old Value New Value Added CWE CWE-674 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 7.0 up to (excluding) 7.1.3 Added Reference Type kernel.org: https://git.kernel.org/stable/c/8371cc5c0a2cc2a71b3dcfd47ff1f7fcfc526a5e Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/a60f25a800846ab8e5a13f8a9d05111f2aee55a7 Types: Patch -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 20, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 19, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'd2ca50606f5f0235d7780c1cd73b6614a5d07620', 'lessThan': '8371cc5c0a2cc2a71b3dcfd47ff1f7fcfc526a5e', 'versionType': 'git'}, {'status': 'affected', 'version': 'd2ca50606f5f0235d7780c1cd73b6614a5d07620', 'lessThan': 'a60f25a800846ab8e5a13f8a9d05111f2aee55a7', 'versionType': 'git'}], 'programFiles': ['fs/nfsd/nfs4proc.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '7.0'}, {'status': 'unaffected', 'version': '0', 'lessThan': '7.0', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '7.1.3', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['fs/nfsd/nfs4proc.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: nfsd: fix dead ACL conflict guard in nfsd4_create nfsd4_create() steals create->cr_dpacl/cr_pacl into the local nfsd_attrs via the designated initializer, then immediately sets the source pointers to NULL. The subsequent conflict guard tests the already-nilled source fields, making it permanently dead code: if (create->cr_acl) { if (create->cr_dpacl || create->cr_pacl) /* always false */ When a client encodes both FATTR4_WORD0_ACL and FATTR4_WORD2_POSIX_{DEFAULT,ACCESS}_ACL in the same CREATE fattr bitmap, nfsd4_acl_to_attr() overwrites attrs.na_pacl/na_dpacl without releasing the originals, leaking two posix_acl slab objects per request. Repeated requests cause unbounded slab exhaustion. Fix by checking attrs.na_dpacl/na_pacl (the stolen values) instead of the nilled create->cr_dpacl/cr_pacl, matching the correct pattern already used in nfsd4_setattr(). Added Reference https://git.kernel.org/stable/c/8371cc5c0a2cc2a71b3dcfd47ff1f7fcfc526a5e Added Reference https://git.kernel.org/stable/c/a60f25a800846ab8e5a13f8a9d05111f2aee55a7