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PatchSiren cyber security CVE debrief

CVE-2026-53395 Linux CVE debrief

A Linux kernel vulnerability, CVE-2026-53395, was resolved in nfsd4_create(). The issue involves a dead ACL conflict guard, leading to a memory leak of two posix_acl slab objects per request, causing unbounded slab exhaustion. This vulnerability affects Linux kernel users and administrators, who should be aware of the issue and ensure their systems are updated.

Vendor
Linux
Product
Unknown
CVSS
Unknown
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-19
Original CVE updated
2026-07-19
Advisory published
2026-07-19
Advisory updated
2026-07-19

Who should care

Linux kernel users and administrators, as well as operators, platforms, vulnerability-management teams, and security teams, should be aware of this vulnerability and ensure their systems are updated.

Technical summary

The vulnerability is in the Linux kernel's nfsd4_create() function. 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, leading to a memory leak. This issue can cause slab exhaustion and should be addressed by updating the Linux kernel to the latest version.

Defensive priority

Medium

Recommended defensive actions

  • Update Linux kernel to the latest version
  • Review and apply patches for nfsd4_create() function
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
  • Review compensating controls for exposed systems while remediation is scheduled and verified.
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review.
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented.
  • Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.

Evidence notes

The CVE record was published on 2026-07-19T12:16:50.597Z and has not been modified since then. The NVD entry is currently Received. There is limited information available about the vulnerability, and defenders should verify the affected scope and severity with the official advisory or CVE record.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-19T12:16:50.597Z and has not been modified since then.