--- cve: "CVE-2026-53393" severity: "LOW" cvss: 3.1 epss: "0.1%" vendor: "Linux" kev: false exploited: false published: "2026-07-19 12:16:50" tags: [cve, security, low] source: tsecurity.de CVE-Dossier exported: "2026-09-22T09:38:13+02:00" --- # CVE-2026-53393 > 3.1 LOW ## Beschreibung 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. ## Patch verfügbar (OSV) - Kernel ≥ 5.10.261 - Kernel ≥ 5.15.212 - Kernel ≥ 6.1.178 - Kernel ≥ 6.6.145 - Kernel ≥ 6.12.95 - Kernel ≥ 6.18.38 - Kernel ≥ 7.1.3 ## Referenzen - - - - - - - - --- _Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-53393) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_