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NVD / CVE Program· CNA Linux

CVE-2026-53399: nfsd: release layout stid on setlease failure

Noroxi assessment

Priority: Monitor (action score 39/100)

  • 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: 0.66% (FIRST EPSS); higher than 51.4% of all records.
  • 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 2e0a5d6d62600b8c614d1b55e50ef94035d6adf9, 30d55c8aabb261bc3f427d6b9aae7ef6206063f9, 48a586e382e4db1dbf958d44b63e081df5f8ed04; azl3 kernel 6.6.144.1-1 on Azure Linux 3.0 6.6.145.2-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 2e0a5d6d62600b8c614d1b55e50ef94035d6adf9, 30d55c8aabb261bc3f427d6b9aae7ef6206063f9, 48a586e382e4db1dbf958d44b63e081df5f8ed04; azl3 kernel 6.6.144.1-1 on Azure Linux 3.0 6.6.145.2-1 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: release layout stid on setlease failure nfs4_alloc_stid() publishes the new stid into cl->cl_stateids via idr_alloc_cyclic() under cl_lock before returning to nfsd4_alloc_layout_stateid(). When nfsd4_layout_setlease() then fails, the error path frees the layout stateid directly with kmem_cache_free() without ever calling idr_remove(), leaving the IDR slot pointing at freed slab memory. Any subsequent IDR walker (states_show, client teardown) dereferences the dangling pointer. The correct teardown for an IDR-published stid is nfs4_put_stid(), which removes the IDR slot under cl_lock, dispatches sc_free (nfsd4_free_layout_stateid) to release ls->ls_file via nfsd4_close_layout(), and drops the nfs4_file reference in its tail. A second issue blocks that switch: nfsd4_free_layout_stateid() unconditionally inspects ls->ls_fence_work via delayed_work_pending() under ls_lock, but INIT_DELAYED_WORK(&ls->ls_fence_work, ...) currently runs only after the setlease call. On the setlease-failure path the destructor would touch an uninitialized delayed_work. nfsd4_alloc_layout_stateid() nfs4_alloc_stid() /* idr_alloc_cyclic under cl_lock */ nfsd4_layout_setlease() /* fails */ nfs4_put_stid() nfsd4_free_layout_stateid() delayed_work_pending(&ls->ls_fence_work) /* needs INIT */ nfsd4_close_layout() /* nfsd_file_put(ls->ls_file) */ put_nfs4_file() Fix by hoisting the ls_fenced / ls_fence_delay / INIT_DELAYED_WORK initialization above the nfsd4_layout_setlease() call, and replace the manual nfsd_file_put + put_nfs4_file + kmem_cache_free cleanup with a single nfs4_put_stid(stp).

CriticalCVSS 9.8 · v3.1—No exploit Fix available
Published
Jul 19, 2026
Updated
Oct 19, 2026
EPSS
0.6% · 51th percentile

Report tools

JSON

Action score

39

Monitor

Low priority for now.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.6%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
9.8
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.

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  • 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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  • when EPSS rises 20 points in a week

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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.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel4.0 and later · before 5.10.261
  • linux linux kernel5.11 and later · before 5.15.212
  • linux linux kernel5.16 and later · before 6.1.178
  • linux linux kernel6.2 and later · before 6.6.145
  • linux linux kernel6.7 and later · before 6.12.96
  • linux linux kernel6.13 and later · before 6.18.39
  • linux linux kernel6.19 and later · before 7.1.3

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

    • 4.0affected
    • c5c707f96fc9a6e5a57ca5baac892673270abe3d and later · before d788ef40a7517d22c97ab01700e4ae4c611b6f2faffected · git
    • c5c707f96fc9a6e5a57ca5baac892673270abe3d and later · before 2e0a5d6d62600b8c614d1b55e50ef94035d6adf9affected · git
    • c5c707f96fc9a6e5a57ca5baac892673270abe3d and later · before 7bbb7ce74051c8be4b69ff44ce3db370600dae61affected · git
    • c5c707f96fc9a6e5a57ca5baac892673270abe3d and later · before 48a586e382e4db1dbf958d44b63e081df5f8ed04affected · git
    • c5c707f96fc9a6e5a57ca5baac892673270abe3d and later · before d369e5edfaaf83a448016e2f1da392b2174be801affected · git
    • c5c707f96fc9a6e5a57ca5baac892673270abe3d and later · before 8dee7c278f1c2b5bb80e17a6281c3812fc8b0cddaffected · git
    • c5c707f96fc9a6e5a57ca5baac892673270abe3d and later · before 83c2b7797742339bb768f83935f7ca33950db138affected · git
    • c5c707f96fc9a6e5a57ca5baac892673270abe3d and later · before 30d55c8aabb261bc3f427d6b9aae7ef6206063f9affected · git
    • before 4.0not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:10kernelbefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2
AlmaLinux:10kernel-64kbefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2
AlmaLinux:10kernel-64k-corebefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2
AlmaLinux:10kernel-64k-debugbefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2
AlmaLinux:10kernel-64k-debug-corebefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2
AlmaLinux:10kernel-64k-debug-develbefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2
AlmaLinux:10kernel-64k-debug-devel-matchedbefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2
AlmaLinux:10kernel-64k-debug-modulesbefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-corebefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-extrabefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2
AlmaLinux:10kernel-64k-develbefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2
AlmaLinux:10kernel-64k-devel-matchedbefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2
AlmaLinux:10kernel-64k-modulesbefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2
AlmaLinux:10kernel-64k-modules-corebefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2
AlmaLinux:10kernel-64k-modules-extrabefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2
AlmaLinux:10kernel-abi-stablelistsbefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2
AlmaLinux:10kernel-corebefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2
AlmaLinux:10kernel-cross-headersbefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2
AlmaLinux:10kernel-debugbefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2
AlmaLinux:10kernel-debug-corebefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2
AlmaLinux:10kernel-debug-develbefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2
AlmaLinux:10kernel-debug-devel-matchedbefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2
AlmaLinux:10kernel-debug-modulesbefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2
AlmaLinux:10kernel-debug-modules-corebefore 6.12.0-211.50.1.el10_26.12.0-211.50.1.el10_2

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-53397Jul 19, 2026 · nfsd: fix posix_acl leak on SETACL decode failure
    30Monitor
  • ← EarlierCVE-2026-53398Jul 19, 2026 · NFSD: Fix SECINFO_NO_NAME decode error cleanup
    39Monitor
  • Later →CVE-2026-53400Jul 19, 2026 · i2c: core: fix adapter registration race
    31Monitor

Remediation

Which version to upgrade to

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

Product / packageFixed versionSource
Linux Linux2e0a5d6d62600b8c614d1b55e50ef94035d6adf9Vendor (CNA)
Linux Linux30d55c8aabb261bc3f427d6b9aae7ef6206063f9Vendor (CNA)
Linux Linux48a586e382e4db1dbf958d44b63e081df5f8ed04Vendor (CNA)
Linux Linux7bbb7ce74051c8be4b69ff44ce3db370600dae61Vendor (CNA)
Linux Linux83c2b7797742339bb768f83935f7ca33950db138Vendor (CNA)
Linux Linux8dee7c278f1c2b5bb80e17a6281c3812fc8b0cddVendor (CNA)
Linux Linuxd369e5edfaaf83a448016e2f1da392b2174be801Vendor (CNA)
Linux Linuxd788ef40a7517d22c97ab01700e4ae4c611b6f2fVendor (CNA)
azl3 kernel 6.6.144.1-1 on Azure Linux 3.06.6.145.2-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
almalinux:kernel6.12.0-211.50.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k6.12.0-211.50.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-core6.12.0-211.50.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug6.12.0-211.50.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-core6.12.0-211.50.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-devel6.12.0-211.50.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-devel-matched6.12.0-211.50.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules6.12.0-211.50.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules-core6.12.0-211.50.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules-extra6.12.0-211.50.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-devel6.12.0-211.50.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-devel-matched6.12.0-211.50.1.el10_2 · AlmaLinux:10Package registry (OSV)
debian:linux6.1.180-1 · Debian:12Package registry (OSV)
debian:linux-6.126.12.100-1~deb12u1 · Debian:12Package registry (OSV)
opensuse:kernel-source7.1.4-1.1 · openSUSE:TumbleweedPackage registry (OSV)
red hat:kernel-64k-debug-debuginfo0:6.12.0-211.50.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debug-devel0:6.12.0-211.50.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debug-devel-matched0:6.12.0-211.50.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debuginfo0:6.12.0-211.50.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-devel0:6.12.0-211.50.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-devel-matched0:6.12.0-211.50.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)

+8

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+1% in 7 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.

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
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-476 · NULL Pointer Dereference

CVSS vector

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

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

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

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

References

Show all references (7 more)

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

All records