CVE-2026-89776Hinoki check available

Kernel-memory disclosure via undersized VXLAN attributes

Published Sep 16, 2026 · Updated Sep 16, 2026

Out-of-bounds read in affected Linux kernels allows local users to disclose kernel memory through a short VXLAN VNI filter attribute. The VXLAN VNI filter policy accepts undersized GROUP or GROUP6 netlink payloads, and nla_get_in_addr() performs an unconditional four-byte load that copies uninitialized slab bytes into remote_ip for RTM_GETTUNNEL to return. Access requires reaching the VNI filter netlink path; the reported consequence is disclosure of up to three bytes per short GROUP attribute, with no integrity or availability impact described.

CVSS severityUnavailable
Unscored
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Out-of-bounds read in affected Linux kernels allows local users to disclose kernel memory through a short VXLAN VNI filter attribute. The VXLAN VNI filter policy accepts undersized GROUP or GROUP6 netlink payloads, and nla_get_in_addr() performs an unconditional four-byte load that copies uninitialized slab bytes into remote_ip for RTM_GETTUNNEL to return. Access requires reaching the VNI filter netlink path; the reported consequence is disclosure of up to three bytes per short GROUP attribute, with no integrity or availability impact described.

The record

CVE
CVE-2026-89776
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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=5.18
  2. Affected versionversion=f9c4bb0b245cee35ef66f75bf409c9573d934cf9 <47bfcc871576eaef6c8edab6749acd4b317306ea
  3. Affected versionversion=f9c4bb0b245cee35ef66f75bf409c9573d934cf9 <984f831dda31b3a18f47454cf64989f65402879e
  4. Affected versionversion=f9c4bb0b245cee35ef66f75bf409c9573d934cf9 <a9ec10815199f9879ba080241dc555efb1daf324
  5. Affected versionversion=f9c4bb0b245cee35ef66f75bf409c9573d934cf9 <ad32e564c62ebf5ba76dd60a22af52c69d54d17b
  6. Affected versionversion=f9c4bb0b245cee35ef66f75bf409c9573d934cf9 <daebc7064a1b4c12c98e52c4bceede7f2fcd573c
  7. Affected versionversion=f9c4bb0b245cee35ef66f75bf409c9573d934cf9 <e12c4663529699f457b2988c1dfedf4d13b3b3be

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=5.18; version=f9c4bb0b245cee35ef66f75bf409c9573d934cf9 <47bfcc871576eaef6c8edab6749acd4b317306ea; version=f9c4bb0b245cee35ef66f75bf409c9573d934cf9 <984f831dda31b3a18f47454cf64989f65402879e; version=f9c4bb0b245cee35ef66f75bf409c9573d934cf9 <a9ec10815199f9879ba080241dc555efb1daf324; version=f9c4bb0b245cee35ef66f75bf409c9573d934cf9 <ad32e564c62ebf5ba76dd60a22af52c69d54d17b; version=f9c4bb0b245cee35ef66f75bf409c9573d934cf9 <daebc7064a1b4c12c98e52c4bceede7f2fcd573c; version=f9c4bb0b245cee35ef66f75bf409c9573d934cf9 <e12c4663529699f457b2988c1dfedf4d13b3b3be

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

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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