Answer in brief
CVE-2026-53392 records a High severity (CVSS 7.5) vulnerability in NFSv4/flexfiles: reject zero filehandle version count. 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.
CVSS is 7.5. 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.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=d67ae825a59d639e4d8b82413af84d854617a87e <9033591535c066726f5b505126ccb4068b98fa4f || >=d67ae825a59d639e4d8b82413af84d854617a87e <18cc6d57a14fa65ab2a2b52279f549041c4bc9cf || >=d67ae825a59d639e4d8b82413af84d854617a87e <be7829715e341b42846437dd9e721005db59f0cc || >=d67ae825a59d639e4d8b82413af84d854617a87e <eeabb9020721db6bc132e68eeae380b8d4fb4b04 || >=d67ae825a59d639e4d8b82413af84d854617a87e <7779c85028a0676fb190cde4f0c540f4f8e97761 || >=d67ae825a59d639e4d8b82413af84d854617a87e <d8c90c7cc061265d5f2813a1f5c82ef2f4707e67 || >=d67ae825a59d639e4d8b82413af84d854617a87e <2131ed64b767ffa8bcdb3677d90f3964e39aabc8 || >=d67ae825a59d639e4d8b82413af84d854617a87e <2c6bb3c40bc24f6aa8dfbe6fe98c3ad6389203f2 | 9033591535c066726f5b505126ccb4068b98fa4f, 18cc6d57a14fa65ab2a2b52279f549041c4bc9cf, be7829715e341b42846437dd9e721005db59f0cc, eeabb9020721db6bc132e68eeae380b8d4fb4b04, 7779c85028a0676fb190cde4f0c540f4f8e97761, d8c90c7cc061265d5f2813a1f5c82ef2f4707e67, 2131ed64b767ffa8bcdb3677d90f3964e39aabc8, 2c6bb3c40bc24f6aa8dfbe6fe98c3ad6389203f2 |
| Linux/Linuxgeneric | 4.0 | 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 5, 2026
In the Linux kernel, the following vulnerability has been resolved: NFSv4/flexfiles: reject zero filehandle version count ff_layout_alloc_lseg() decodes the filehandle-version array count from the flexfiles layout body. The value is used as the count for kzalloc_objs(), and the current code only rejects NULL. A zero count yields ZERO_SIZE_PTR, which can be stored in dss_info->fh_versions even though later flexfiles paths assume that at least one filehandle version exists. Reject fh_count == 0 before the allocation, matching the existing zero version_count validation in the flexfiles GETDEVICEINFO parser. A QEMU/KASAN run with a malformed flexfiles layout hit: KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] RIP: 0010:ff_layout_encode_ff_layoutupdate.isra.0+0x15f/0x750 ff_layout_encode_layoutreturn+0x683/0x970 nfs4_xdr_enc_layoutreturn+0x278/0x3a0 Kernel panic - not syncing: Fatal exception The patched kernel rejects the malformed layout without KASAN/oops/panic, and a valid fh_count=1 regression still opens, reads, and unmounts cleanly.
Quoted source text, attributed separately from HOL analysis.