CVE-2026-90114Hinoki check available

Unpredictable returns via descending VLAN tunnel ranges

Published Sep 17, 2026 · Updated Sep 17, 2026

Uninitialized data in Linux bridge VLAN tunnels allows local users to obtain unpredictable return values via malformed Netlink requests. In br_process_vlan_tunnel_info, signed-to-unsigned conversion lets descending VLAN and tunnel ranges pass the span comparison, skipping the loop that initializes err before its post-loop use. Reachability requires CAP_NET_ADMIN in the relevant network namespace and VLAN-tunnel mode on a bridge port; the upstream finding establishes unpredictable request results, not a demonstrated crash or privilege escalation.

CVSS severity3.3
Low
EPSS probability0.22%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Uninitialized data in Linux bridge VLAN tunnels allows local users to obtain unpredictable return values via malformed Netlink requests. In br_process_vlan_tunnel_info, signed-to-unsigned conversion lets descending VLAN and tunnel ranges pass the span comparison, skipping the loop that initializes err before its post-loop use. Reachability requires CAP_NET_ADMIN in the relevant network namespace and VLAN-tunnel mode on a bridge port; the upstream finding establishes unpredictable request results, not a demonstrated crash or privilege escalation.

The record

CVE
CVE-2026-90114
Published
Sep 17, 2026
Updated
Sep 17, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Sep 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 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=5.9
  2. Affected versionversion=94339443686b36d3223bc032b7947267474e2679 <0874a6d5275091429ec4c675c54c53a8776665ae
  3. Affected versionversion=94339443686b36d3223bc032b7947267474e2679 <1181f6bad009408a259bab6aaf0681f11b487972
  4. Affected versionversion=94339443686b36d3223bc032b7947267474e2679 <434849b21ef56b09d16e6366b2a230002f363e45
  5. Affected versionversion=94339443686b36d3223bc032b7947267474e2679 <4b0f5b25f114651f03058395b490626c4444875e
  6. Affected versionversion=94339443686b36d3223bc032b7947267474e2679 <5a8e0e3a18b5e3172343b8479c5d04187f5b4795
  7. Affected versionversion=94339443686b36d3223bc032b7947267474e2679 <b74a072d8fb71d3c9ffba4a17d5943e63266fb38
  8. Affected versionversion=94339443686b36d3223bc032b7947267474e2679 <bd741b819ff1c239d26cc5b0f0e6b1fd4e67ed17
  9. Affected versionversion=94339443686b36d3223bc032b7947267474e2679 <c0444d7499f113d6b7803ef0175591464e17525e

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=5.9; version=94339443686b36d3223bc032b7947267474e2679 <0874a6d5275091429ec4c675c54c53a8776665ae; version=94339443686b36d3223bc032b7947267474e2679 <1181f6bad009408a259bab6aaf0681f11b487972; version=94339443686b36d3223bc032b7947267474e2679 <434849b21ef56b09d16e6366b2a230002f363e45; version=94339443686b36d3223bc032b7947267474e2679 <4b0f5b25f114651f03058395b490626c4444875e; version=94339443686b36d3223bc032b7947267474e2679 <5a8e0e3a18b5e3172343b8479c5d04187f5b4795; version=94339443686b36d3223bc032b7947267474e2679 <b74a072d8fb71d3c9ffba4a17d5943e63266fb38; version=94339443686b36d3223bc032b7947267474e2679 <bd741b819ff1c239d26cc5b0f0e6b1fd4e67ed17; version=94339443686b36d3223bc032b7947267474e2679 <c0444d7499f113d6b7803ef0175591464e17525e

Published CVSS scores

4.9TenableAV:L/AC:L/Au:N/C:N/I:N/A:C
5.5TenableCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
3.3Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

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.

Activity data is delayed. The latest report is Sep 28, 2026.

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No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
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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