Vulnerability · CVE-2026-89705
In the Linux kernel, the following vulnerability has been resolved: nfsd: restore rq_status_counter to even on all nfsd_dispatch() exit paths nfsd_dispatch() sets rq_s…
Published Sep 11, 2026 · catalog updated Oct 15, 2026 · the affected product
Check if you run it
No confirmed exploitation is on record for CVE-2026-89705. EPSS is 0.16%. Act only if a listed version of the affected product is installed.
Gaps on this record
- No plain product name is stored. The page cannot tell you which product to check.
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- High7.1
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.16%
- Remediation
- Not established
- Affected products
- See sources for product scope
In the Linux kernel, the following vulnerability has been resolved: nfsd: restore rq_status_counter to even on all nfsd_dispatch() exit paths nfsd_dispatch() sets rq_status_counter to an odd value once a request has been decoded, and back to an even value once it has been fully processed, forming a seq-lock like protocol with the lockless reader in nfsd_nl_rpc_status_get_dumpit(). Only the fully successful path restored the counter to even. The cache-hit (RC_REPLY), drop (RC_DROPIT / RQ_DROPME) and encode-error paths all return after the odd-valued store without ever bringing the counter back to even. Once one of those paths is taken, rq_status_counter is left odd: the next request's decode ORs in 1 (still odd) and only a subsequent successful encode restores even. While stuck odd, the dumpit reader treats the rqstp fields as stable and its retry check compares against the same unchanging odd value, so it never detects concurrent mutation. This exposes actively mutating fields (e.g. args->ops / args->opcnt during compound decode and release) to the lockless reader, which can read past the end of the 8-element inline ops array. Add a helper that advances the counter to the next even value and call it on every return path that follows the odd-valued store. The decode-error path is left untouched as it is reached before the counter is set odd.
No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.
How to fix CVE-2026-89705
Recommended remediation
No required-action text, fix commit, or clear fixed-version range is stored yet.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-89705. EPSS is 0.16%. Act only if a listed version of the affected product is installed.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
No weakness class is stored. EPSS 0.16%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Sep 11, 2026 · NIST NVD
Detected
In the Linux kernel, the following vulnerability has been resolved: nfsd: restore rq_status_counter to even on all nfsd_dispatch() exit paths nfsd_dispatch() sets rq_status_counter to an odd value once a request has been decoded, and back to an even value once it has been fully processed, forming a seq-lock like protocol with the lockless reader in nfsd_nl_rpc_status_get_dumpit(). Only the fully s
Oct 15, 2026 · NIST NVD
Updated
In the Linux kernel, the following vulnerability has been resolved: nfsd: restore rq_status_counter to even on all nfsd_dispatch() exit paths nfsd_dispatch() sets rq_status_counter to an odd value once a request has been decoded, and back to an even value once it has been fully processed, forming a seq-lock like protocol with the lockless reader in nfsd_nl_rpc_status_get_dumpit(). Only the fully s
Sources
- CVE.orgVulnerability recordCVE-2026-89705
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-89705
30-day exploitation probability 0.2%
first.org - NIST NVDVulnerability recordCVE-2026-89705
In the Linux kernel, the following vulnerability has been resolved: nfsd: restore rq_status_counter to even on all nfsd_dispatch() exit paths nfsd_dispatch() sets rq_status_counter to an odd value once a request has been decoded, and back to an even value once it has been fully
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.