CVE-2026-89817Public exploit

Out-of-bounds read via unterminated TV mode name

Published Sep 16, 2026 · Updated Sep 16, 2026

Out-of-bounds read in the Linux GUD driver allows physically proximate attackers to trigger a kernel warning through a malformed USB display. gud_connector_add_tv_mode passes fixed-size device-supplied names to drm_mode_create_tv_properties_legacy, where strlen reads beyond a slot lacking a NUL byte. Reachability requires an attached or emulated GUD device that returns the malformed TV mode name; the demonstrated consequence is an out-of-bounds kernel read.

CVSS severityUnavailable
Unscored
EPSS probabilityUnavailable
No score available in this record
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in the Linux GUD driver allows physically proximate attackers to trigger a kernel warning through a malformed USB display. gud_connector_add_tv_mode passes fixed-size device-supplied names to drm_mode_create_tv_properties_legacy, where strlen reads beyond a slot lacking a NUL byte. Reachability requires an attached or emulated GUD device that returns the malformed TV mode name; the demonstrated consequence is an out-of-bounds kernel read.

The record

CVE
CVE-2026-89817
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1200
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=40e1a70b4aedf2859a1829991b48ef0ebe650bf2 <08c8ec28547987e55a90c662f8795e05c2925498
  2. Affected versionversion=40e1a70b4aedf2859a1829991b48ef0ebe650bf2 <500cb24cd61bad8a2747ddfc49b7034899c82d94
  3. Affected versionversion=40e1a70b4aedf2859a1829991b48ef0ebe650bf2 <6ea61f1d4cbaa0db937e31bffc041fb8afeacf52
  4. Affected versionversion=40e1a70b4aedf2859a1829991b48ef0ebe650bf2 <89210cb5ff8fdbe055c97ac688be2268f6c815ae
  5. Affected versionversion=40e1a70b4aedf2859a1829991b48ef0ebe650bf2 <9096edfd6f2edbc79612b482547e0972edbcfe4b
  6. Affected versionversion=40e1a70b4aedf2859a1829991b48ef0ebe650bf2 <b86438a5c6b0250ccb07dd380184d1e70e0dea6c
  7. Affected versionversion=40e1a70b4aedf2859a1829991b48ef0ebe650bf2 <d0f3312f7800eb0e00d1264f66104c788f43dd69
  8. Affected versionversion=5.13

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=40e1a70b4aedf2859a1829991b48ef0ebe650bf2 <08c8ec28547987e55a90c662f8795e05c2925498; version=40e1a70b4aedf2859a1829991b48ef0ebe650bf2 <500cb24cd61bad8a2747ddfc49b7034899c82d94; version=40e1a70b4aedf2859a1829991b48ef0ebe650bf2 <6ea61f1d4cbaa0db937e31bffc041fb8afeacf52; version=40e1a70b4aedf2859a1829991b48ef0ebe650bf2 <89210cb5ff8fdbe055c97ac688be2268f6c815ae; version=40e1a70b4aedf2859a1829991b48ef0ebe650bf2 <9096edfd6f2edbc79612b482547e0972edbcfe4b; version=40e1a70b4aedf2859a1829991b48ef0ebe650bf2 <b86438a5c6b0250ccb07dd380184d1e70e0dea6c; version=40e1a70b4aedf2859a1829991b48ef0ebe650bf2 <d0f3312f7800eb0e00d1264f66104c788f43dd69; version=5.13

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1200Hardware Additions

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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