{"cve":"CVE-2026-53393","nvd":{"published":"2026-07-19T12:16:50.367","modified":"2026-08-17T05:17:13.763","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: reset write verifier on deferred writeback errors\n\nnfsd_vfs_write() and nfsd_commit() both call filemap_check_wb_err() to\ndetect deferred writeback errors, but neither rotates the server's write\nverifier (nn->writeverf) when this check fails. Every other\ndurable-storage-failure path in these functions calls\ncommit_reset_write_verifier() before returning an error.\n\nThe missing rotation means clients holding UNSTABLE write data under the\ncurrent verifier will COMMIT, receive the unchanged verifier back, and\nconclude their data is durable — silently dropping data that failed\nwriteback. This violates the UNSTABLE+COMMIT durability contract\n(RFC 1813 §3.3.7, RFC 8881 §18.32).\n\nAdd commit_reset_write_verifier() calls at both filemap_check_wb_err()\nerror sites, matching the pattern used by adjacent error paths in the\nsame functions. The helper already filters -EAGAIN and -ESTALE\ninternally, so the calls are unconditionally safe.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/1dd664b39774a9c89b72de8e59bf9ef4b3aaff2e","https://git.kernel.org/stable/c/2090b05803faab8a9fa62fbff871007862cac1b7","https://git.kernel.org/stable/c/4367afc119c51e17a616f6908772b7e2c2c4013f","https://git.kernel.org/stable/c/43b65d2997963e80e8d8d86520bcb1e0751227de","https://git.kernel.org/stable/c/666e837b247fcadf2d8d508b9b0e49d720393eb4"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:45:36.895656543+00:00"},"epss":{"cve":"CVE-2026-53393","score":0.00129,"percentile":0.02563,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}