nfsd: fix dead ACL conflict guard in nfsd4_create (CVE-2026-53395) | HOL Guard CVE

High · CVSS 7.5CVE-2026-53395

nfsd: fix dead ACL conflict guard in nfsd4_create

Answer in brief

CVE-2026-53395 records a High severity (CVSS 7.5) vulnerability in nfsd: fix dead ACL conflict guard in nfsd4_create. 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.

Published Jul 19, 2026Updated Aug 17, 2026Source checked Sep 20, 2026First seen by HOL Aug 5, 2026Material review Aug 17, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.5
Exploitation: Not marked as known exploited
Affected software: 3 mapped packages or products
Fix availability: Available

Why this deserves its current priority

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.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Affected products and reported versions
Product	Affected versions	Fixed versions
cpe:2.3:o:linux:linux_kernel::::::::	Not reported	Not reported

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=d2ca50606f5f0235d7780c1cd73b6614a5d07620 <8371cc5c0a2cc2a71b3dcfd47ff1f7fcfc526a5e \|\| >=d2ca50606f5f0235d7780c1cd73b6614a5d07620 <a60f25a800846ab8e5a13f8a9d05111f2aee55a7	8371cc5c0a2cc2a71b3dcfd47ff1f7fcfc526a5e, a60f25a800846ab8e5a13f8a9d05111f2aee55a7
Linux/Linuxgeneric	7.0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 8371cc5c0a2cc2a71b3dcfd47ff1f7fcfc526a5e if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Jul 19, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 17, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 5, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: nfsd: fix dead ACL conflict guard in nfsd4_create nfsd4_create() steals create->cr_dpacl/cr_pacl into the local nfsd_attrs via the designated initializer, then immediately sets the source pointers to NULL. The subsequent conflict guard tests the already-nilled source fields, making it permanently dead code: if (create->cr_acl) { if (create->cr_dpacl || create->cr_pacl) /* always false */ When a client encodes both FATTR4_WORD0_ACL and FATTR4_WORD2_POSIX_{DEFAULT,ACCESS}_ACL in the same CREATE fattr bitmap, nfsd4_acl_to_attr() overwrites attrs.na_pacl/na_dpacl without releasing the originals, leaking two posix_acl slab objects per request. Repeated requests cause unbounded slab exhaustion. Fix by checking attrs.na_dpacl/na_pacl (the stolen values) instead of the nilled create->cr_dpacl/cr_pacl, matching the correct pattern already used in nfsd4_setattr().

Quoted source text, attributed separately from HOL analysis.