In the Linux kernel, the following vulnerability has been resolved: nfsd: fix posix_acl leak on SETACL decode failure nfsaclsvc_decode_setaclargs()… (CVE-2026-53397)
A vulnerability in the Linux kernel's NFS server code causes a memory leak of posix_acl structures when decoding SETACL requests fails. Specifically, if decoding the default ACL fails after successfully decoding the access ACL, the access ACL is leaked because cleanup routines do not properly release it on decode failure. This leak persists for the lifetime of the server process. The issue has been fixed by introducing new release functions that properly free both ACLs on all code paths, including decode failures.
AI Analysis
Technical Summary
The Linux kernel's NFS server implementations for NFSv2 and NFSv3 call nfs_stream_decode_acl() twice during SETACL request decoding, transferring ownership of allocated posix_acl structures to argp->acl_access and argp->acl_default. If the first call succeeds but the second fails, the decoder returns false, skipping the main processing function and causing the release function to only call fh_put() without releasing the allocated ACLs. This results in a posix_acl memory leak for the server's lifetime. The fix adds dedicated release functions that free both ACLs regardless of decode success, ensuring no memory leak occurs.
Potential Impact
The vulnerability causes a memory leak of posix_acl structures in the NFS server component of the Linux kernel. Over time, this could lead to increased memory usage and potential resource exhaustion on the affected server. There is no indication of direct code execution or privilege escalation from this leak. No known exploits are reported in the wild.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. The vulnerability description indicates that a fix has been implemented by adding proper release functions to free leaked ACLs on decode failure. Users should monitor official Linux kernel advisories for patches addressing CVE-2026-53397 and apply them once available. Until patched, no specific workaround is described.
In the Linux kernel, the following vulnerability has been resolved: nfsd: fix posix_acl leak on SETACL decode failure nfsaclsvc_decode_setaclargs()… (CVE-2026-53397)
Description
A vulnerability in the Linux kernel's NFS server code causes a memory leak of posix_acl structures when decoding SETACL requests fails. Specifically, if decoding the default ACL fails after successfully decoding the access ACL, the access ACL is leaked because cleanup routines do not properly release it on decode failure. This leak persists for the lifetime of the server process. The issue has been fixed by introducing new release functions that properly free both ACLs on all code paths, including decode failures.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel's NFS server implementations for NFSv2 and NFSv3 call nfs_stream_decode_acl() twice during SETACL request decoding, transferring ownership of allocated posix_acl structures to argp->acl_access and argp->acl_default. If the first call succeeds but the second fails, the decoder returns false, skipping the main processing function and causing the release function to only call fh_put() without releasing the allocated ACLs. This results in a posix_acl memory leak for the server's lifetime. The fix adds dedicated release functions that free both ACLs regardless of decode success, ensuring no memory leak occurs.
Potential Impact
The vulnerability causes a memory leak of posix_acl structures in the NFS server component of the Linux kernel. Over time, this could lead to increased memory usage and potential resource exhaustion on the affected server. There is no indication of direct code execution or privilege escalation from this leak. No known exploits are reported in the wild.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. The vulnerability description indicates that a fix has been implemented by adding proper release functions to free leaked ACLs on decode failure. Users should monitor official Linux kernel advisories for patches addressing CVE-2026-53397 and apply them once available. Until patched, no specific workaround is described.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-mpc7-4w3v-v47r
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-53397"]
- Ecosystems
- []
- Database Specific Severity
- null
- Cvss Version
- null
Threat ID: 6a5d27ad2a4a8d5989132269
Added to database: 07/19/2026, 19:38:21 UTC
Last enriched: 07/19/2026, 20:23:23 UTC
Last updated: 07/20/2026, 17:26:47 UTC
Views: 12
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.