CVE-2021-47046

Local kernel-memory disclosure via missing HDCP offset

Published Feb 28, 2024 · Updated May 11, 2026

Out-of-bounds read in Linux kernel AMD display HDCP handling allows local users to access adjacent kernel memory via an HDCP message. The hdmi_14_process_transaction() function indexes hdcp_i2c_offsets[] for HDCP_MESSAGE_ID_WRITE_CONTENT_STREAM_TYPE, but the array lacks that entry and reads one element past its end. Reachability requires local low-privileged access, the AMD display driver, and an HDCP-capable display path; the disclosed effect is memory disclosure.

CVSS severity7.8
High
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Linux kernel AMD display HDCP handling allows local users to access adjacent kernel memory via an HDCP message. The hdmi_14_process_transaction() function indexes hdcp_i2c_offsets[] for HDCP_MESSAGE_ID_WRITE_CONTENT_STREAM_TYPE, but the array lacks that entry and reads one element past its end. Reachability requires local low-privileged access, the AMD display driver, and an HDCP-capable display path; the disclosed effect is memory disclosure.

The record

CVE
CVE-2021-47046
Published
Feb 28, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-193
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 28, 2024CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=4c283fdac08abf3211533f70623c90a34f41d08d <080bd41d6478a64edf96704fddcda52b1fd5fed7
  2. Affected versionversion=4c283fdac08abf3211533f70623c90a34f41d08d <403c4528e5887af3deb9838cb77a557631d1e138
  3. Affected versionversion=4c283fdac08abf3211533f70623c90a34f41d08d <6a58310d5d1e5b02d0fc9b393ba540c9367bced5
  4. Affected versionversion=4c283fdac08abf3211533f70623c90a34f41d08d <8e6fafd5a22e7a2eb216f5510db7aab54cc545c1
  5. Affected versionversion=5.5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4c283fdac08abf3211533f70623c90a34f41d08d <080bd41d6478a64edf96704fddcda52b1fd5fed7; version=4c283fdac08abf3211533f70623c90a34f41d08d <403c4528e5887af3deb9838cb77a557631d1e138; version=4c283fdac08abf3211533f70623c90a34f41d08d <6a58310d5d1e5b02d0fc9b393ba540c9367bced5; version=4c283fdac08abf3211533f70623c90a34f41d08d <8e6fafd5a22e7a2eb216f5510db7aab54cc545c1; version=5.5

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-193Off-by-one Error

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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