CVE-2026-89724 media: vicodec: fix out-of-bounds write in FWHT encoder
An out-of-bounds write in the Linux kernel vicodec driver allows attackers to corrupt kernel heap memory, potentially leading to code execution or privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-89724?
CVE-2026-89724 is a high-severity memory corruption vulnerability in Linux, published on 11 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-89724?
How do I fix CVE-2026-89724?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-89724 being exploited?
There is no known exploitation of CVE-2026-89724 in the wild and no public exploit code.
Sources
Also known as AZL-100483, BELL-CVE-2026-89724, DEBIAN-CVE-2026-89724, GHSA-8cqc-p4qr-2jqq, UBUNTU-CVE-2026-89724.