CVE-2026-53393nfsd: reset write verifier on deferred writeback errors
- 5.5MediumCVSS base score
- 0.13%Exploitation in 30 daysEPSS · top 97% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By Linux
- 40 days later
· 40 days later
Published
- 4 months later
· 4 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Analyzed | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.13% · top 97% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.
Affected products
- affected f14816f2f928c560d28ba344af689f56efcd6f55 – < b8e5894e56cff70fa245628fe16f0ad6367f8090
- affected 3145fe0ebb16e1715ad541a301bc6675c8375fcd – < bc2baca02ec56da7707a74ed5d340b0a1dff1841
- affected 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb – < 43b65d2997963e80e8d8d86520bcb1e0751227de
- affected 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb – < 666e837b247fcadf2d8d508b9b0e49d720393eb4
- affected 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb – < 1dd664b39774a9c89b72de8e59bf9ef4b3aaff2e
- affected 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb – < 4367afc119c51e17a616f6908772b7e2c2c4013f
- affected 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb – < b027cca33c97354149fcc0ddeede4525c41093cd
- affected 555dbf1a9aac6d3150c8b52fa35f768a692f4eeb – < 2090b05803faab8a9fa62fbff871007862cac1b7
- affected 5.10.124 – < 5.10.261
- affected 5.15.49 – < 5.15.212
- affected 5.17
- unaffected < 5.17
- unaffected 5.10.261 – ≤ 5.10.*
- unaffected 5.15.212 – ≤ 5.15.*
- unaffected 6.1.178 – ≤ 6.1.*
- unaffected 6.6.145 – ≤ 6.6.*
- unaffected 6.12.95 – ≤ 6.12.*
- unaffected 6.18.38 – ≤ 6.18.*
- unaffected 7.1.3 – ≤ 7.1.*
- unaffected 7.2 – ≤ *
References
References8
- https://git.kernel.org/stable/c/b8e5894e56cff70fa245628fe16f0ad6367f8090 (opens in a new tab)
- https://git.kernel.org/stable/c/bc2baca02ec56da7707a74ed5d340b0a1dff1841 (opens in a new tab)
- https://git.kernel.org/stable/c/43b65d2997963e80e8d8d86520bcb1e0751227de (opens in a new tab)
- https://git.kernel.org/stable/c/666e837b247fcadf2d8d508b9b0e49d720393eb4 (opens in a new tab)
- https://git.kernel.org/stable/c/1dd664b39774a9c89b72de8e59bf9ef4b3aaff2e (opens in a new tab)
- https://git.kernel.org/stable/c/4367afc119c51e17a616f6908772b7e2c2c4013f (opens in a new tab)
- https://git.kernel.org/stable/c/b027cca33c97354149fcc0ddeede4525c41093cd (opens in a new tab)
- https://git.kernel.org/stable/c/2090b05803faab8a9fa62fbff871007862cac1b7 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-45515 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://cveledger.app/cve/CVE-2026-53393)Record last updated .