CVE-2026-89671· NVD / CVE Program· CNA Linux

nfsd: gate nfs3 setacl by argp->mask

Noroxi assessment

Priority: Monitor (action score 36/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.50% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: Linux Linux 3be1d8611dae4829e4608007db29f4a8748c37b2, 453d7198a0ab07a12d46e0575861ac7b932da17e, 68a80b26efdff1d09f8ae1773c6a915abb9e191d; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 3be1d8611dae4829e4608007db29f4a8748c37b2, 453d7198a0ab07a12d46e0575861ac7b932da17e, 68a80b26efdff1d09f8ae1773c6a915abb9e191d; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: nfsd: gate nfs3 setacl by argp->mask nfsd3_proc_setacl() calls set_posix_acl() unconditionally for both ACL_TYPE_ACCESS and ACL_TYPE_DEFAULT, passing argp->acl_access and argp->acl_default verbatim. The NFSv3 ACL decoder only populates those pointers when the corresponding mask bit is set: nfs3svc_decode_setaclargs() if (args->mask & NFS_ACL) decode into acl_access if (args->mask & NFS_DFACL) decode into acl_default /* otherwise the pointer stays NULL (pc_argzero) */ nfsd3_proc_setacl() set_posix_acl(.., ACL_TYPE_ACCESS, argp->acl_access) set_posix_acl(.., ACL_TYPE_DEFAULT, argp->acl_default) set_posix_acl(idmap, dentry, type, NULL) is the VFS "remove this ACL type" operation. A NULL pointer that means "the client did not send this arm" is therefore indistinguishable from "the client asked to remove this ACL". A SETACL with mask=NFS_ACL silently drops the directory's default ACL; mask=0 drops both. The sibling nfsd3_proc_getacl() already consults argp->mask before touching each arm; mirror that in setacl. Fix by wrapping each set_posix_acl() call in the matching mask bit check and initializing error to 0 before inode_lock so that a request with neither bit set leaves the on-disk ACLs untouched and returns nfs_ok. The out_drop_lock path and the unconditional posix_acl_release() at out: are preserved; both NULL-tolerate the skipped arms.

CriticalCVSS 9.1 · v3.1—No exploit Fix available

Pre-auth

EUVD-2026-76583

Published: Sep 11, 2026
Updated: Oct 19, 2026
EPSS: 0.5% · 41th percentile
CWE: —

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 36 / 40 · 9.1 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.5%

CISA SSVC decision

Exploitation: none
Automatable: yes
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · Linux: 9.1; NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

Linux Linux
- 2.6.13affected
- a257cdd0e2179630d3201c32ba14d7fcb3c3a055 and later · before 3be1d8611dae4829e4608007db29f4a8748c37b2affected · git
- a257cdd0e2179630d3201c32ba14d7fcb3c3a055 and later · before 68a80b26efdff1d09f8ae1773c6a915abb9e191daffected · git
- a257cdd0e2179630d3201c32ba14d7fcb3c3a055 and later · before b3bff820d068ea59767d4e91a3258231a879da5faffected · git
- a257cdd0e2179630d3201c32ba14d7fcb3c3a055 and later · before ff99ed007f065198fd723152405c22aa558f700baffected · git
- a257cdd0e2179630d3201c32ba14d7fcb3c3a055 and later · before 453d7198a0ab07a12d46e0575861ac7b932da17eaffected · git
- before 2.6.13not affected · semver
- 6.6.157 and later · up to and including 6.6.*not affected · semver
- 6.12.109 and later · up to and including 6.12.*not affected · semver
- 6.18.50 and later · up to and including 6.18.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:12	linux	from 0	—
Debian:12	linux-6.12	before 6.12.111-1~deb12u1	6.12.111-1~deb12u1
Debian:13	linux	before 6.12.111-1	6.12.111-1
Debian:14	linux	before 7.2.6-1	7.2.6-1

Same product

linux: all records

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Published before and after this one in the same product

← EarlierCVE-2026-89669Sep 11, 2026 · nfsd: initialize copy-notify stateid before publishing it
39Monitor
← EarlierCVE-2026-89670Sep 11, 2026 · nfsd: hold rcu across localio cmpxchg retry
31Monitor
Later →CVE-2026-89672Sep 11, 2026 · nfsd: gate nfs2 setacl by argp->mask
36Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
Linux Linux	3be1d8611dae4829e4608007db29f4a8748c37b2	Vendor (CNA)
Linux Linux	453d7198a0ab07a12d46e0575861ac7b932da17e	Vendor (CNA)
Linux Linux	68a80b26efdff1d09f8ae1773c6a915abb9e191d	Vendor (CNA)
Linux Linux	b3bff820d068ea59767d4e91a3258231a879da5f	Vendor (CNA)
Linux Linux	ff99ed007f065198fd723152405c22aa558f700b	Vendor (CNA)
azl3 kernel 6.6.150.1-1 on Azure Linux 3.0	—	Microsoft (MSRC)
azl3 kernel 6.6.152.1-1 on Azure Linux 3.0	6.6.157.1-1 · Release Notes	Microsoft (MSRC)
debian:linux	6.12.111-1 · Debian:13	Package registry (OSV)
debian:linux-6.12	6.12.111-1~deb12u1 · Debian:12	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-26-1085 · Sep 14, 2026(Linux Kernel Güvenlik Bildirimi)

All national notices →

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: none

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: None

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

SSVC exploitation— → noneOct 16, 2026, 9:07 PM UTC
Fix✗ → ✓Sep 28, 2026, 10:07 PM UTC

For records you follow, these changes also arrive as notifications. →

References

git.kernel.org/stable/c/3be1d8611dae4829e4608007db29f4a8748c37b2

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records