Answer in brief
CVE-2026-53393 records a Unknown severity vulnerability in nfsd: reset write verifier on deferred writeback errors. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2026-53393 records a Unknown severity vulnerability in nfsd: reset write verifier on deferred writeback errors. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=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 | b8e5894e56cff70fa245628fe16f0ad6367f8090, bc2baca02ec56da7707a74ed5d340b0a1dff1841, 43b65d2997963e80e8d8d86520bcb1e0751227de, 666e837b247fcadf2d8d508b9b0e49d720393eb4, 1dd664b39774a9c89b72de8e59bf9ef4b3aaff2e, 4367afc119c51e17a616f6908772b7e2c2c4013f, b027cca33c97354149fcc0ddeede4525c41093cd, 2090b05803faab8a9fa62fbff871007862cac1b7, 5.10.261, 5.15.212 |
| Linux/Linuxgeneric | 5.17 | Not reported |
Published upstream
Jul 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 17, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 17, 2026
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.
Quoted source text, attributed separately from HOL analysis.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=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 | b8e5894e56cff70fa245628fe16f0ad6367f8090, bc2baca02ec56da7707a74ed5d340b0a1dff1841, 43b65d2997963e80e8d8d86520bcb1e0751227de, 666e837b247fcadf2d8d508b9b0e49d720393eb4, 1dd664b39774a9c89b72de8e59bf9ef4b3aaff2e, 4367afc119c51e17a616f6908772b7e2c2c4013f, b027cca33c97354149fcc0ddeede4525c41093cd, 2090b05803faab8a9fa62fbff871007862cac1b7, 5.10.261, 5.15.212 |
| Linux/Linuxgeneric | 5.17 | Not reported |
Published upstream
Jul 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 17, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 17, 2026
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.
Quoted source text, attributed separately from HOL analysis.