5.5
MEDIUM
CVSS 3.1
CVE-2026-53393
nfsd: reset write verifier on deferred writeback errors
Overview
Description
In the Linux kernel, the following vulnerability has been resolved: nfsd: reset write verifier on deferred writeback errors nfsd_vfs_write() and nfsd_commit() both call filemap_check_wb_err() to detect deferred writeback errors, but neither rotates the server's write verifier (nn->writeverf) when this check fails. Every other durable-storage-failure path in these functions calls commit_reset_write_verifier() before returning an error. The missing rotation means clients holding UNSTABLE write data under the current verifier will COMMIT, receive the unchanged verifier back, and conclude their data is durable — silently dropping data that failed writeback. This violates the UNSTABLE+COMMIT durability contract (RFC 1813 §3.3.7, RFC 8881 §18.32). Add commit_reset_write_verifier() calls at both filemap_check_wb_err() error sites, matching the pattern used by adjacent error paths in the same functions. The helper already filters -EAGAIN and -ESTALE internally, so the calls are unconditionally safe.
Details
INFO
Published Date :
July 19, 2026, 12:16 p.m.
Last Modified :
Aug. 17, 2026, 5:17 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework
for assessing the severity of vulnerabilities in software and systems.
We collect and displays CVSS scores from various sources for each CVE.
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
Ensure NFS server write verifier is reset on deferred writeback errors to maintain data integrity.
- Apply kernel updates to reset write verifier on errors.
- Verify NFS server configuration for writeback error handling.
- Confirm data durability contract compliance.
References
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-2026-53393.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-53393 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-2026-53393
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-2026-53393 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-53393 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': 'f14816f2f928c560d28ba344af689f56efcd6f55', 'lessThan': 'b8e5894e56cff70fa245628fe16f0ad6367f8090', 'versionType': 'git'}, {'status': 'affected', 'version': '3145fe0ebb16e1715ad541a301bc6675c8375fcd', 'lessThan': 'bc2baca02ec56da7707a74ed5d340b0a1dff1841', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': '43b65d2997963e80e8d8d86520bcb1e0751227de', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': '666e837b247fcadf2d8d508b9b0e49d720393eb4', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': '1dd664b39774a9c89b72de8e59bf9ef4b3aaff2e', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': '4367afc119c51e17a616f6908772b7e2c2c4013f', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': 'b027cca33c97354149fcc0ddeede4525c41093cd', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': '2090b05803faab8a9fa62fbff871007862cac1b7', 'versionType': 'git'}, {'status': 'affected', 'version': '5.10.124', 'lessThan': '5.10.261', 'versionType': 'semver'}, {'status': 'affected', 'version': '5.15.49', 'lessThan': '5.15.212', 'versionType': 'semver'}], 'programFiles': ['fs/nfsd/vfs.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.17'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.17', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.261', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.212', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.178', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.95', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.38', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'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/vfs.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'f14816f2f928c560d28ba344af689f56efcd6f55', 'lessThan': 'b8e5894e56cff70fa245628fe16f0ad6367f8090', 'versionType': 'git'}, {'status': 'affected', 'version': '3145fe0ebb16e1715ad541a301bc6675c8375fcd', 'lessThan': 'bc2baca02ec56da7707a74ed5d340b0a1dff1841', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': '43b65d2997963e80e8d8d86520bcb1e0751227de', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': '666e837b247fcadf2d8d508b9b0e49d720393eb4', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': '1dd664b39774a9c89b72de8e59bf9ef4b3aaff2e', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': '4367afc119c51e17a616f6908772b7e2c2c4013f', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': 'b027cca33c97354149fcc0ddeede4525c41093cd', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': '2090b05803faab8a9fa62fbff871007862cac1b7', 'versionType': 'git'}, {'status': 'affected', 'version': '5.10.124', 'lessThan': '5.10.261', 'versionType': 'semver'}, {'status': 'affected', 'version': '5.15.49', 'lessThan': '5.15.212', 'versionType': 'semver'}], 'programFiles': ['fs/nfsd/vfs.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.17'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.17', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.261', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.212', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.178', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.95', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.38', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'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/vfs.c'], 'defaultStatus': 'affected'}] -
Initial Analysis by [email protected]
Jul. 29, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE NVD-CWE-noinfo Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.95 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.38 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 7.1.3 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.145 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.10.124 up to (excluding) 5.10.261 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.15.49 up to (excluding) 5.15.212 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.17 up to (excluding) 6.1.178 Added Reference Type kernel.org: https://git.kernel.org/stable/c/1dd664b39774a9c89b72de8e59bf9ef4b3aaff2e Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/2090b05803faab8a9fa62fbff871007862cac1b7 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/4367afc119c51e17a616f6908772b7e2c2c4013f Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/43b65d2997963e80e8d8d86520bcb1e0751227de Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/666e837b247fcadf2d8d508b9b0e49d720393eb4 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/b027cca33c97354149fcc0ddeede4525c41093cd Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/b8e5894e56cff70fa245628fe16f0ad6367f8090 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/bc2baca02ec56da7707a74ed5d340b0a1dff1841 Types: Patch -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 24, 2026
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/43b65d2997963e80e8d8d86520bcb1e0751227de Added Reference https://git.kernel.org/stable/c/666e837b247fcadf2d8d508b9b0e49d720393eb4 Added Reference https://git.kernel.org/stable/c/b8e5894e56cff70fa245628fe16f0ad6367f8090 Added Reference https://git.kernel.org/stable/c/bc2baca02ec56da7707a74ed5d340b0a1dff1841 Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': '1dd664b39774a9c89b72de8e59bf9ef4b3aaff2e', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': '4367afc119c51e17a616f6908772b7e2c2c4013f', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': 'b027cca33c97354149fcc0ddeede4525c41093cd', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': '2090b05803faab8a9fa62fbff871007862cac1b7', 'versionType': 'git'}, {'status': 'affected', 'version': 'f14816f2f928c560d28ba344af689f56efcd6f55', 'versionType': 'git'}, {'status': 'affected', 'version': '3145fe0ebb16e1715ad541a301bc6675c8375fcd', 'versionType': 'git'}, {'status': 'affected', 'version': '5.10.124', 'lessThan': '5.11', 'versionType': 'semver'}, {'status': 'affected', 'version': '5.15.49', 'lessThan': '5.16', 'versionType': 'semver'}], 'programFiles': ['fs/nfsd/vfs.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.17'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.17', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.95', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.38', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'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/vfs.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'f14816f2f928c560d28ba344af689f56efcd6f55', 'lessThan': 'b8e5894e56cff70fa245628fe16f0ad6367f8090', 'versionType': 'git'}, {'status': 'affected', 'version': '3145fe0ebb16e1715ad541a301bc6675c8375fcd', 'lessThan': 'bc2baca02ec56da7707a74ed5d340b0a1dff1841', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': '43b65d2997963e80e8d8d86520bcb1e0751227de', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': '666e837b247fcadf2d8d508b9b0e49d720393eb4', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': '1dd664b39774a9c89b72de8e59bf9ef4b3aaff2e', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': '4367afc119c51e17a616f6908772b7e2c2c4013f', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': 'b027cca33c97354149fcc0ddeede4525c41093cd', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': '2090b05803faab8a9fa62fbff871007862cac1b7', 'versionType': 'git'}, {'status': 'affected', 'version': '5.10.124', 'lessThan': '5.10.261', 'versionType': 'semver'}, {'status': 'affected', 'version': '5.15.49', 'lessThan': '5.15.212', 'versionType': 'semver'}], 'programFiles': ['fs/nfsd/vfs.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.17'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.17', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.261', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.212', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.178', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.95', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.38', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'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/vfs.c'], 'defaultStatus': 'affected'}] -
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': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': '1dd664b39774a9c89b72de8e59bf9ef4b3aaff2e', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': '4367afc119c51e17a616f6908772b7e2c2c4013f', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': 'b027cca33c97354149fcc0ddeede4525c41093cd', 'versionType': 'git'}, {'status': 'affected', 'version': '555dbf1a9aac6d3150c8b52fa35f768a692f4eeb', 'lessThan': '2090b05803faab8a9fa62fbff871007862cac1b7', 'versionType': 'git'}, {'status': 'affected', 'version': 'f14816f2f928c560d28ba344af689f56efcd6f55', 'versionType': 'git'}, {'status': 'affected', 'version': '3145fe0ebb16e1715ad541a301bc6675c8375fcd', 'versionType': 'git'}, {'status': 'affected', 'version': '5.10.124', 'lessThan': '5.11', 'versionType': 'semver'}, {'status': 'affected', 'version': '5.15.49', 'lessThan': '5.16', 'versionType': 'semver'}], 'programFiles': ['fs/nfsd/vfs.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.17'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.17', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.95', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.38', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'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/vfs.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: nfsd: reset write verifier on deferred writeback errors nfsd_vfs_write() and nfsd_commit() both call filemap_check_wb_err() to detect deferred writeback errors, but neither rotates the server's write verifier (nn->writeverf) when this check fails. Every other durable-storage-failure path in these functions calls commit_reset_write_verifier() before returning an error. The missing rotation means clients holding UNSTABLE write data under the current verifier will COMMIT, receive the unchanged verifier back, and conclude their data is durable — silently dropping data that failed writeback. This violates the UNSTABLE+COMMIT durability contract (RFC 1813 §3.3.7, RFC 8881 §18.32). Add commit_reset_write_verifier() calls at both filemap_check_wb_err() error sites, matching the pattern used by adjacent error paths in the same functions. The helper already filters -EAGAIN and -ESTALE internally, so the calls are unconditionally safe. Added Reference https://git.kernel.org/stable/c/1dd664b39774a9c89b72de8e59bf9ef4b3aaff2e Added Reference https://git.kernel.org/stable/c/2090b05803faab8a9fa62fbff871007862cac1b7 Added Reference https://git.kernel.org/stable/c/4367afc119c51e17a616f6908772b7e2c2c4013f Added Reference https://git.kernel.org/stable/c/b027cca33c97354149fcc0ddeede4525c41093cd
EPSS is a daily estimate of the probability of exploitation activity
being observed over the next 30 days. Following chart shows the EPSS
score history of the vulnerability.