Kernel compromise via mutable IB length reread
Published Aug 10, 2026 · Updated Aug 10, 2026
A TOCTOU race in the Linux kernel AMDGPU VCN4 encoder allows local users to corrupt kernel state via crafted command buffers. The vcn_v4_0_ring_patch_cs_in_place path validates an IB parameter length, then rereads that attacker-mutable dword instead of reusing the value returned by vcn_v4_0_enc_find_ib_param(). Access to an AMDGPU VCN4 render node is required; racing the second read can misadvance or stall IB parsing, causing out-of-bounds kernel access or a repeatable service hang.
Summary
What happened
A TOCTOU race in the Linux kernel AMDGPU VCN4 encoder allows local users to corrupt kernel state via crafted command buffers. The vcn_v4_0_ring_patch_cs_in_place path validates an IB parameter length, then rereads that attacker-mutable dword instead of reusing the value returned by vcn_v4_0_enc_find_ib_param(). Access to an AMDGPU VCN4 render node is required; racing the second read can misadvance or stall IB parsing, causing out-of-bounds kernel access or a repeatable service hang.
The record
- CVE
- CVE-2026-68107
- Published
- Aug 10, 2026
- Updated
- Aug 10, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-367, T1068, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 10, 2026CVE publishedPublication date reported by the CVE source.
- Aug 10, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <6.12.101
- Affected versionversion=0 <6.18.42
- Affected versionversion=0 <6.6.148
- Affected versionversion=0 <7.1.6
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <3b4082fabc67c9780b06eb959e59dd92fa79c0f0
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <bbbe6a2a8d8dc87243438d3ffea2083b52d882d9
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <bd868c077f67589ed2a714307ceaade5f246e302
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c309626bf91fa0a0b583575654e6e14e81f818a3
- Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ff6aa542d91d76a185f69bd1997b94a560ff5f6b
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
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
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo