CVE-2026-89669
nfsd: initialize copy-notify stateid before publishing it
Description
In the Linux kernel, the following vulnerability has been resolved: nfsd: initialize copy-notify stateid before publishing it nfsd4_copy_notify() finished initializing the cpntf state after nfs4_alloc_init_cpntf_state() had already linked it into the s2s_cp_stateids IDR and the parent's sc_cp_list, with cs_count == 1 (the membership reference) and none held for the caller. A racing OFFLOAD_CANCEL (crafted cl_id == nn->s2s_cp_cl_id plus the guessable so_id) could reach manage_cpntf_state() and free the entry, turning the caller's subsequent cpn_cnr_stateid read and cp_p_stateid/cp_p_clid writes into use-after-free. The owning clientid was also only recorded after publication, so it could not gate an ownership check in that window. Record cp_p_stateid and cp_p_clid inside nfs4_alloc_init_cpntf_state() before nfs4_init_cp_state() publishes the entry, and return it with an extra reference. The caller reads the stateid under that reference and drops it with nfs4_put_cpntf_state(); on a late error the laundromat reaps the entry.
INFO
Published Date :
Sept. 11, 2026, 8:19 p.m.
Last Modified :
Sept. 14, 2026, 1:19 p.m.
Remotely Exploit :
Yes !
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Update the Linux kernel to resolve the issue.
- Ensure state is initialized before publishing.
- Add reference counting for state management.
- Reap entries on late errors.
References to Advisories, Solutions, and Tools
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CVE-2026-89669.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-89669 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-89669
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-89669 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-89669 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 14, 2026
Action Type Old Value New Value Added Affected Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/89xxx/CVE-2026-89669.json">CVE-2026-89669</a> Added Reference https://git.kernel.org/stable/c/4415a692346a39fdb647cbd717eda510159aaf55 Added Reference https://git.kernel.org/stable/c/863b6e995665472f2af5be2436a874ab6a9e5ac6 Added Reference https://git.kernel.org/stable/c/9caad13b7cfe9ccb90cc405ac77335800e086595 Added Reference https://git.kernel.org/stable/c/d18d36395d973ef7372c8e6724970585f75b5c0b -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 13, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Sep. 11, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: nfsd: initialize copy-notify stateid before publishing it nfsd4_copy_notify() finished initializing the cpntf state after nfs4_alloc_init_cpntf_state() had already linked it into the s2s_cp_stateids IDR and the parent's sc_cp_list, with cs_count == 1 (the membership reference) and none held for the caller. A racing OFFLOAD_CANCEL (crafted cl_id == nn->s2s_cp_cl_id plus the guessable so_id) could reach manage_cpntf_state() and free the entry, turning the caller's subsequent cpn_cnr_stateid read and cp_p_stateid/cp_p_clid writes into use-after-free. The owning clientid was also only recorded after publication, so it could not gate an ownership check in that window. Record cp_p_stateid and cp_p_clid inside nfs4_alloc_init_cpntf_state() before nfs4_init_cp_state() publishes the entry, and return it with an extra reference. The caller reads the stateid under that reference and drops it with nfs4_put_cpntf_state(); on a late error the laundromat reaps the entry. Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/89xxx/CVE-2026-89669.json">CVE-2026-89669</a> Added Reference https://git.kernel.org/stable/c/129643893b79f8a3c6b72045f933fbab5ee424ca Added Reference https://git.kernel.org/stable/c/4cdef96892f4fa6e70c405b6e8f2fd6972f3b64b Added Reference https://git.kernel.org/stable/c/a4d7fedcaaf33e60a01e53eafca9041ef966212f Added Reference https://git.kernel.org/stable/c/e08a3dcaca0505f861e344a387f37f94d95dbdc2