Kernel memory exposure via undersized CXL payload
Published Mar 25, 2026 · Updated Mar 25, 2026
Out-of-bounds read in Linux Kernel allows local users to expose kernel memory or crash the system via a raw CXL mailbox command. The cxl_payload_from_user_allowed() path casts and dereferences an undersized input buffer, causing uuid_equal() to read a 16-byte UUID beyond the allocation. Access to the CXL memory-device ioctl and a malformed raw command are required; the demonstrated result is a KASAN-detected slab over-read.
Summary
What happened
Out-of-bounds read in Linux Kernel allows local users to expose kernel memory or crash the system via a raw CXL mailbox command. The cxl_payload_from_user_allowed() path casts and dereferences an undersized input buffer, causing uuid_equal() to read a 16-byte UUID beyond the allocation. Access to the CXL memory-device ioctl and a malformed raw command are required; the demonstrated result is a KASAN-detected slab over-read.
The record
- CVE
- CVE-2026-23327
- Published
- Mar 25, 2026
- Updated
- Mar 25, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- CWE-125, T1005
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 25, 2026CVE publishedPublication date reported by the CVE source.
- Mar 25, 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?
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- Affected versionversion=5.19
- Affected versionversion=6179045ccc0c6229dc449afc1701dc7fbd40571f <60b5d1f68338aff2c5af0113f04aefa7169c50c2
- Affected versionversion=6179045ccc0c6229dc449afc1701dc7fbd40571f <7c8a7b7f063b7e7ae9bba4cbaa14a5d2fe3a55e1
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
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Technologies
Your stack
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Your stack
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