CVE-2026-53392NFSv4/flexfiles: reject zero filehandle version count
- 7.5HighCVSS base score
- 0.53%Exploitation in 30 daysEPSS · top 55% 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: 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.
Timeline
ID reserved
By Linux
- 40 days later
· 40 days later
Published
- 3 months later
· 3 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 |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Modified | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.53% · top 55% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Affected products
- affected d67ae825a59d639e4d8b82413af84d854617a87e – < 9033591535c066726f5b505126ccb4068b98fa4f
- affected d67ae825a59d639e4d8b82413af84d854617a87e – < 18cc6d57a14fa65ab2a2b52279f549041c4bc9cf
- affected d67ae825a59d639e4d8b82413af84d854617a87e – < be7829715e341b42846437dd9e721005db59f0cc
- affected d67ae825a59d639e4d8b82413af84d854617a87e – < eeabb9020721db6bc132e68eeae380b8d4fb4b04
- affected d67ae825a59d639e4d8b82413af84d854617a87e – < 7779c85028a0676fb190cde4f0c540f4f8e97761
- affected d67ae825a59d639e4d8b82413af84d854617a87e – < d8c90c7cc061265d5f2813a1f5c82ef2f4707e67
- affected d67ae825a59d639e4d8b82413af84d854617a87e – < 2131ed64b767ffa8bcdb3677d90f3964e39aabc8
- affected d67ae825a59d639e4d8b82413af84d854617a87e – < 2c6bb3c40bc24f6aa8dfbe6fe98c3ad6389203f2
- affected 4.0
- unaffected < 4.0
- 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 6.12.96 – ≤ 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/9033591535c066726f5b505126ccb4068b98fa4f (opens in a new tab)
- https://git.kernel.org/stable/c/18cc6d57a14fa65ab2a2b52279f549041c4bc9cf (opens in a new tab)
- https://git.kernel.org/stable/c/be7829715e341b42846437dd9e721005db59f0cc (opens in a new tab)
- https://git.kernel.org/stable/c/eeabb9020721db6bc132e68eeae380b8d4fb4b04 (opens in a new tab)
- https://git.kernel.org/stable/c/7779c85028a0676fb190cde4f0c540f4f8e97761 (opens in a new tab)
- https://git.kernel.org/stable/c/d8c90c7cc061265d5f2813a1f5c82ef2f4707e67 (opens in a new tab)
- https://git.kernel.org/stable/c/2131ed64b767ffa8bcdb3677d90f3964e39aabc8 (opens in a new tab)
- https://git.kernel.org/stable/c/2c6bb3c40bc24f6aa8dfbe6fe98c3ad6389203f2 (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-2026-45514 (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)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-53392)Record last updated .