CVE-2026-89691

Kernel memory disclosure via stale compound operation count

Published Sep 11, 2026 · Updated Sep 11, 2026

Out-of-bounds read in Linux 6.7 allows local users to disclose adjacent kernel slab memory through the nfsd RPC status interface. nfsd4_release_compoundargs resets args->ops to the eight-entry inline iops array after freeing a larger buffer but fails to clear the retained operation count. The read requires an odd rq_status_counter after an nfsd dispatch error, and a subsequent netlink status dump can return entries beyond iops to userspace.

CVSS severityUnavailable
Unscored
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Linux 6.7 allows local users to disclose adjacent kernel slab memory through the nfsd RPC status interface. nfsd4_release_compoundargs resets args->ops to the eight-entry inline iops array after freeing a larger buffer but fails to clear the retained operation count. The read requires an odd rq_status_counter after an nfsd dispatch error, and a subsequent netlink status dump can return entries beyond iops to userspace.

The record

CVE
CVE-2026-89691
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1005
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6.7
  2. Affected versionversion=bd9d6a3efa9709e653aafbeb859289feccb8e70c <58bcdfb2b2e412088839ae740b1a95154dc0b8d0
  3. Affected versionversion=bd9d6a3efa9709e653aafbeb859289feccb8e70c <ae4c38555e81563b8dc5eae55ffd70f0ea97aa5a
  4. Affected versionversion=bd9d6a3efa9709e653aafbeb859289feccb8e70c <c1a4f7b1848f95302df598217e1c7a1410c2d0c5
  5. Affected versionversion=bd9d6a3efa9709e653aafbeb859289feccb8e70c <e879148867bd4c4cac42e063ffaffa187dddc6fe

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=6.7; version=bd9d6a3efa9709e653aafbeb859289feccb8e70c <58bcdfb2b2e412088839ae740b1a95154dc0b8d0; version=bd9d6a3efa9709e653aafbeb859289feccb8e70c <ae4c38555e81563b8dc5eae55ffd70f0ea97aa5a; version=bd9d6a3efa9709e653aafbeb859289feccb8e70c <c1a4f7b1848f95302df598217e1c7a1410c2d0c5; version=bd9d6a3efa9709e653aafbeb859289feccb8e70c <e879148867bd4c4cac42e063ffaffa187dddc6fe

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1005Data from Local System

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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