In the Linux kernel, the following vulnerability has been resolved: NFSD: free copynotify stateid in nfs4_free_ol_stateid() Typically copynotify… (CVE-2025-40273)
A use-after-free vulnerability in the Linux kernel's NFS server (nfsd) was resolved by properly freeing associated copynotify stateids in the nfs4_free_ol_stateid() function. The issue occurs when a parent stateid is freed without freeing its associated copynotify stateids, leading to list corruption and kernel warnings or crashes. This can happen after a client reboot and session recreation, causing internal kernel errors and potential denial of service.
AI Analysis
Technical Summary
The Linux kernel NFS server (nfsd) had a vulnerability where copynotify stateids associated with a parent stateid were not freed correctly in nfs4_free_ol_stateid(). When a client reboots and creates a new session, the previous open state is freed but its copynotify stateid remains, causing list corruption during cleanup (laundromat). This leads to kernel warnings and internal errors (BUG), potentially causing system instability or crashes. The patch fixes this by freeing the copynotify stateid when the parent stateid is freed, preventing list corruption.
Potential Impact
Improper freeing of kernel objects leads to list corruption, causing kernel warnings and internal errors (BUG). This can result in system instability or crashes (denial of service). The vulnerability affects the Linux kernel's NFS server component, impacting confidentiality, integrity, and availability as indicated by the CVSS vector.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, monitor for kernel updates addressing this issue and consider applying kernel patches or updates as recommended by the Linux kernel maintainers.
In the Linux kernel, the following vulnerability has been resolved: NFSD: free copynotify stateid in nfs4_free_ol_stateid() Typically copynotify… (CVE-2025-40273)
Description
A use-after-free vulnerability in the Linux kernel's NFS server (nfsd) was resolved by properly freeing associated copynotify stateids in the nfs4_free_ol_stateid() function. The issue occurs when a parent stateid is freed without freeing its associated copynotify stateids, leading to list corruption and kernel warnings or crashes. This can happen after a client reboot and session recreation, causing internal kernel errors and potential denial of service.
CVSS v3.1
Score 8.8high
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel NFS server (nfsd) had a vulnerability where copynotify stateids associated with a parent stateid were not freed correctly in nfs4_free_ol_stateid(). When a client reboots and creates a new session, the previous open state is freed but its copynotify stateid remains, causing list corruption during cleanup (laundromat). This leads to kernel warnings and internal errors (BUG), potentially causing system instability or crashes. The patch fixes this by freeing the copynotify stateid when the parent stateid is freed, preventing list corruption.
Potential Impact
Improper freeing of kernel objects leads to list corruption, causing kernel warnings and internal errors (BUG). This can result in system instability or crashes (denial of service). The vulnerability affects the Linux kernel's NFS server component, impacting confidentiality, integrity, and availability as indicated by the CVSS vector.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, monitor for kernel updates addressing this issue and consider applying kernel patches or updates as recommended by the Linux kernel maintainers.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-q23q-5v8c-h3gr
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2025-40273"]
- Database Specific Severity
- HIGH
- Cvss Version
- 3.1
Threat ID: 6a6b72d59c2644c7f8479905
Added to database: 07/30/2026, 15:50:45 UTC
Last enriched: 07/30/2026, 17:38:33 UTC
Last updated: 09/10/2026, 19:38:47 UTC
Views: 11
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.