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CVE Record

CVE-2025-68803: NFSD: NFSv4 file creation neglects setting ACL

In the Linux kernel, the following vulnerability has been resolved: NFSD: NFSv4 file creation neglects setting ACL An NFSv4 client that sets an ACL with a named principal during file creation retrieves the ACL afterwards, and finds that it is only a default ACL (based on the mode bits) and not the ACL that was requested during file creation. This violates RFC 8881 section 6.4.1.3: "the ACL attribute is set as given". The issue occurs in nfsd_create_setattr(), which calls nfsd_attrs_valid() to determine whether to call nfsd_setattr(). However, nfsd_attrs_valid() checks only for iattr changes and security labels, but not POSIX ACLs. When only an ACL is present, the function returns false, nfsd_setattr() is skipped, and the POSIX ACL is never applied to the inode. Subsequently, when the client retrieves the ACL, the server finds no POSIX ACL on the inode and returns one generated from the file's mode bits rather than returning the originally-specified ACL.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This Linux kernel NFSD issue can cause an NFSv4 server to ignore an ACL requested during file creation. The file is created, but the intended named-principal ACL is not applied, and later reads show a default ACL derived from mode bits. The main concern is silent access-control drift on NFS-hosted files.

Executive priority

Treat this as a targeted access-control correctness issue. It deserves timely patch review for NFS file servers, especially where ACLs protect sensitive shared data, but current sources do not support emergency exploitation claims.

Technical view

In nfsd_create_setattr(), nfsd_attrs_valid() checks iattr changes and security labels but not POSIX ACLs. If only an ACL is supplied, nfsd_setattr() is skipped and the inode never receives the POSIX ACL. This violates RFC 8881 behavior for setting ACL attributes during NFSv4 file creation.

Likely exposure

Exposure is mainly Linux systems acting as NFSv4 servers with NFSD enabled, especially environments that create files with named-principal ACLs. The bundle lists affected Linux kernel versions and stable commit references but does not provide CPEs or a CVSS score.

Exploitation context

The source bundle does not show KEV listing or active exploitation. This appears to be a logic flaw causing incorrect ACL application, not a documented remote code execution issue. Business impact depends on whether default mode-derived ACLs are less restrictive than intended.

Researcher notes

Key evidence is the kernel description: ACL-only create attributes bypass nfsd_setattr() because nfsd_attrs_valid() ignores POSIX ACL presence. Validate behavior by comparing requested create-time ACLs with retrieved ACLs on affected kernels, without assuming exploitability beyond incorrect ACL persistence.

Mitigation direction

  • Inventory Linux NFSv4 servers using NFSD.
  • Check distribution or kernel vendor guidance for fixed packages.
  • Map deployed kernels against the affected versions in the CVE bundle.
  • Prioritize systems relying on named-principal NFSv4 ACLs.
  • Review sensitive files created through NFSv4 during the vulnerable window.
  • If unpatched, verify and apply intended ACLs after file creation.

Validation and detection

  • Confirm whether NFSD and NFSv4 service are enabled.
  • Check running kernel versions on NFS servers.
  • Review whether workflows set ACLs during NFSv4 file creation.
  • Test in a controlled environment that requested ACLs persist after creation.
  • Audit representative files for expected named-principal ACL entries.
Prepared
Confidence
medium
Sources
10

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
1ADP providers
9Source links

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

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ADP provider summaries

siemens-SADPADP container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxc5409ce523af40d5c3019717bc5b4f72038d48be, d52acd23a327cada5fb597591267cfc09f08bb1d, c0cbe70742f4a70893cd6e5f6b10b6e89b6db95b, c0cbe70742f4a70893cd6e5f6b10b6e89b6db95b, c0cbe70742f4a70893cd6e5f6b10b6e89b6db95b, c0cbe70742f4a70893cd6e5f6b10b6e89b6db95b, c0cbe70742f4a70893cd6e5f6b10b6e89b6db95b, 5.10.220, 5.15.154unaffected
LinuxLinux6.0, 0, 5.10.248, 5.15.198, 6.1.160, 6.6.121, 6.12.64, 6.18.3, 6.19affected
Weakness

CWE details

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