Skip to content
VulniPulse
Advisory severityHigh7.0Red Hat Linux

High [CVE-2026-53396] fix posix_acl leak and ignored error in nfsd4_create_file

This high-severity Red Hat Linux advisory covers CVE-2026-53396.

Aggregated and source-linked by VulniPulse. Data sources, validation and limitations.

CVE-2026-53396 Source published Source updated

VulniPulse record published Record updated

CVE-2026-53396
Affected products & platforms
Red Hat LinuxUnclassified
Open source advisory

Get an email when Red Hat Linux publishes the next one.

See Red Hat Linux's last 90 days of advisories first. Then choose one product with live alerts free for life, or a free month of real-time alerts on everything with the severity, the fixed version and the vendor's link (card needed, then US$15/month; we email you before the first charge).

Alert me about Red Hat Linux

Summary

In the Linux kernel, the following vulnerability has been resolved: nfsd: fix posix_acl leak and ignored error in nfsd4_create_file nfsd4_create_file() has two bugs in its ACL handling: The return value of nfsd4_acl_to_attr() is silently discarded.

When the NFSv4-to-POSIX ACL conversion fails (e.g., -EINVAL for unsupported ACE types), the file is created without any ACL and the client receives NFS4_OK. This violates RFC 7530/8881 which require the server to reject unsupported attributes on CREATE.

When start_creating() fails after ACL attributes have been populated in attrs (either via nfsd4_acl_to_attr or via ownership transfer from open->op_dpacl/op_pacl), the function jumps to out_write which skips nfsd_attrs_free(). The posix_acl allocations are leaked.

A client can trigger this repeatedly with OPEN(CREATE), ACL attributes, and an invalid filename (e.g., longer than NAME_MAX). Fix both by capturing the nfsd4_acl_to_attr() return value and by changing the early error paths to jump to out instead of out_write.

Initialize child to ERR_PTR(-EINVAL) so that end_creating() is safe to call even if start_creating() was never reached. A flaw was found in the Linux kernel's Network File System (NFS) daemon (nfsd) within the nfsd4_create_file() function.

Affected versions

No affected-version range was extracted from the source record. The vendor advisory is authoritative. Check it before change work.

Official advisory · medium-confidence parse· fetched 7 days ago·verify at source

Fixed versions

No fixed release is recorded yet. That does not prove no patch exists. Confirm against the vendor advisory.

Official advisory · medium-confidence parse· fetched 7 days ago·verify at source

Mitigation

The source record does not include mitigation steps. That does not mean no fix exists. Read the vendor advisory below for the authoritative guidance.

Official advisory · medium-confidence parse· fetched 7 days ago·verify at source

All Red Hat Linux advisories

iPhone and Android apps · New on the App Store

Monitor future Red Hat Linux CVEs from your phone.

Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 34 official vendor sources and 160+ reviewed platform categories.

Discussion(0)

No comments yet. Share field notes, upgrade gotchas, or questions — verify against the vendor advisory before acting on community advice.

Sign in to join the discussion.