CVE-2026-53393
Last modified
CVE-2026-53393 is a vulnerability of currently unknown severity. 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. EPSS estimates a 0.18% chance of exploitation in the next 30 days.
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.
Metrics
Affected Software
Source: CNA advisory (CVE.org). NVD analysis pending.
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | >= f14816f2f928c560d28ba344af689f56efcd6f55, < b8e5894e56cff70fa245628fe16f0ad6367f8090; >= 3145fe0ebb16e1715ad541a301bc6675c8375fcd, < bc2baca02ec56da7707a74ed5d340b0a1dff1841; >= 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb, < 43b65d2997963e80e8d8d86520bcb1e0751227de; >= 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb, < 666e837b247fcadf2d8d508b9b0e49d720393eb4; >= 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb, < 1dd664b39774a9c89b72de8e59bf9ef4b3aaff2e; >= 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb, < 4367afc119c51e17a616f6908772b7e2c2c4013f; >= 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb, < b027cca33c97354149fcc0ddeede4525c41093cd; >= 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb, < 2090b05803faab8a9fa62fbff871007862cac1b7; >= 5.10.124, < 5.10.261; >= 5.15.49, < 5.15.212 |
| Linux | Linux | 5.17 |
References
Timeline
- Published
- Last Modified
- Status
- Awaiting Analysis
Frequently Asked Questions
What is CVE-2026-53393?
How severe is CVE-2026-53393?
How do I fix CVE-2026-53393?
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2026
- CVE-2026-53388In the Linux kernel, the following vulnerability has been re…7.8
- CVE-2026-53389In the Linux kernel, the following vulnerability has been re…7.8
- CVE-2026-5339A vulnerability was detected in Tenda G103 1.0.0.5. The impa…8.8
- CVE-2026-53390In the Linux kernel, the following vulnerability has been re…8.1
- CVE-2026-53391In the Linux kernel, the following vulnerability has been re…7.5
- CVE-2026-53392In the Linux kernel, the following vulnerability has been re…7.5
- CVE-2026-53394In the Linux kernel, the following vulnerability has been re…7.5
- CVE-2026-53395In the Linux kernel, the following vulnerability has been re…7.5
- CVE-2026-53396In the Linux kernel, the following vulnerability has been re…7.1
- CVE-2026-53397In the Linux kernel, the following vulnerability has been re…7.5
- CVE-2026-53398In the Linux kernel, the following vulnerability has been re…9.8
- CVE-2026-53399In the Linux kernel, the following vulnerability has been re…9.8
Are you affected by CVE-2026-53393?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST