CVE-2026-90387Hinoki check available

Local privilege escalation via incorrect SWIOTLB free

Published Sep 17, 2026 · Updated Sep 18, 2026

Memory corruption in affected Linux kernel builds starting with 6.6 allows local users to gain kernel privileges through ordinary I/O. The swiotlb_init_io_tlb_pool() function reconstructs a direct-map address instead of retaining the remapped DMA atomic-pool address, so swiotlb_free_tlb() frees an address the pool cannot recognize. Exploitation requires an ARM64 realm guest with CONFIG_DMA_DIRECT_REMAP and forced unencrypted DMA; the bad free can corrupt allocator metadata, expose stale mappings, or crash the guest.

CVSS severity7.8
High
EPSS probability0.16%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Memory corruption in affected Linux kernel builds starting with 6.6 allows local users to gain kernel privileges through ordinary I/O. The swiotlb_init_io_tlb_pool() function reconstructs a direct-map address instead of retaining the remapped DMA atomic-pool address, so swiotlb_free_tlb() frees an address the pool cannot recognize. Exploitation requires an ARM64 realm guest with CONFIG_DMA_DIRECT_REMAP and forced unencrypted DMA; the bad free can corrupt allocator metadata, expose stale mappings, or crash the guest.

The record

CVE
CVE-2026-90387
Published
Sep 17, 2026
Updated
Sep 18, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1068, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 18, 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=6.6
  2. Affected versionversion=79636caad3618e2b38457f6e298c9b31ba82b489 <35e0103177826430b5df888b1506239d41e76ab5
  3. Affected versionversion=79636caad3618e2b38457f6e298c9b31ba82b489 <45507dcb0847e96add4455274b12df0eca6590b4
  4. Affected versionversion=79636caad3618e2b38457f6e298c9b31ba82b489 <57d29044d0f29a76c6ec0c112c8c7371d5608dc7
  5. Affected versionversion=79636caad3618e2b38457f6e298c9b31ba82b489 <68bf3ebd8e7020dae58e8aa14c7d482738bff9a8
  6. Affected versionversion=79636caad3618e2b38457f6e298c9b31ba82b489 <c1f4d7763cdf1b9e0d35c14aa6f52d0512a36319

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.6; version=79636caad3618e2b38457f6e298c9b31ba82b489 <35e0103177826430b5df888b1506239d41e76ab5; version=79636caad3618e2b38457f6e298c9b31ba82b489 <45507dcb0847e96add4455274b12df0eca6590b4; version=79636caad3618e2b38457f6e298c9b31ba82b489 <57d29044d0f29a76c6ec0c112c8c7371d5608dc7; version=79636caad3618e2b38457f6e298c9b31ba82b489 <68bf3ebd8e7020dae58e8aa14c7d482738bff9a8; version=79636caad3618e2b38457f6e298c9b31ba82b489 <c1f4d7763cdf1b9e0d35c14aa6f52d0512a36319

Published CVSS scores

3.6Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:L
7.8Linux CNACVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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.

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

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1068Exploitation for Privilege Escalation
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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