NFSD: fix nfs4_file access extra count in nfsd4_add_rdaccess_to_wrdeleg
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: NFSD: fix nfs4_file access extra count in nfsd4_add_rdaccess_to_wrdeleg In nfsd4_add_rdaccess_to_wrdeleg, if fp->fi_fds[O_RDONLY] is already set by another thread, __nfs4_file_get_access should not be called to increment the nfs4_file access count since that was already done by the thread that added READ access to the file. The extra fi_access count in nfs4_file can prevent the corresponding nfsd_file from being freed. When stopping nfs-server service, these extra access counts trigger a BUG in kmem_cache_destroy() that shows nfsd_file object remaining on __kmem_cache_shutdown. This problem can be reproduced by running the Git project's test suite over NFS.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 6.18.4 to before 6.18.33 | 6.18.33 | Patch available | CNA |
| Linux | Linux | 6.19 and later | 6.18.33, 7.0.10, 7.1 | Patch available | CNA |
- Linux VendorLinux Affected 6.18.4 to before 6.18.33 Fixed in 6.18.33 Patch available CNA
- Linux VendorLinux Affected 6.19 and later Fixed in 6.18.33, 7.0.10, 7.1 Patch available CNA
CPE configurations NVD · 7
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 6.18.4 to before 6.18.33; 6.19.1 to before 7.0.10 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:-:*:*:*:*:*:* | 6.19 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:* | 6.19 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:* | 6.19 rc5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc6:*:*:*:*:*:* | 6.19 rc6 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc7:*:*:*:*:*:* | 6.19 rc7 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.19:rc8:*:*:*:*:*:* | 6.19 rc8 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 6.18.4 to before 6.18.33; 6.19.1 to before 7.0.10 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:-:*:*:*:*:*:* Versions 6.19 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc4:*:*:*:*:*:* Versions 6.19 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc5:*:*:*:*:*:* Versions 6.19 rc5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc6:*:*:*:*:*:* Versions 6.19 rc6 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc7:*:*:*:*:*:* Versions 6.19 rc7 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.19:rc8:*:*:*:*:*:* Versions 6.19 rc8 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.18.33
- Fix · CNA Linux (Linux) Fixed in 6.18.33, 7.0.10, 7.1
Red Hat 1 advisory
- RHSA-2026:61887 Released 2026-09-01 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.50.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.50.1.el10_2, kernel-64k-devel-6.12.0-211.50.1.el10_2 +12
- Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.50.1.el10_2, kernel-64k-6.12.0-211.50.1.el10_2, kernel-64k-core-6.12.0-211.50.1.el10_2 +29
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.50.1.el10_2, libperf-6.12.0-211.50.1.el10_2
- Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.50.1.el10_2, kernel-rt-64k-6.12.0-211.50.1.el10_2, kernel-rt-64k-core-6.12.0-211.50.1.el10_2 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.50.1.el10_2, kernel-rt-core-6.12.0-211.50.1.el10_2, kernel-rt-debug-6.12.0-211.50.1.el10_2 +9
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:61887 |
| Red Hat Enterprise Linux BaseOS (v. 10) | Fixed | RHSA-2026:61887 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) | Fixed | RHSA-2026:61887 |
| Red Hat Enterprise Linux Real Time (v. 10) | Fixed | RHSA-2026:61887 |
| Red Hat Enterprise Linux Real Time for NFV (v. 10) | Fixed | RHSA-2026:61887 |
Not affected: 4 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2026-53026
- 2026-10-03 Alias added: GHSA-5968-j93g-c79f
References
More Linux Kernel vulnerabilities
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- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2026-53026 · CVE Program
- CVE-2026-53026 · NVD
- FIRST EPSS
- GHSA-5968-j93g-c79f · GitHub Advisory Database · CC BY 4.0
- CVE-2026-53026 · Red Hat security data · CC BY 4.0
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