CVE-2024-42121

Kernel memory overrun via invalid HDCP message index

Published Jul 30, 2024 · Updated May 11, 2026

Array-index validation failure in affected Linux kernels allows local users to trigger memory overruns during AMD HDCP handling. The hdcp_ddc.c read and write paths accept MOD_HDCP_MESSAGE_ID_INVALID (-1) as msg_id and use it to index message tables without first rejecting it. Reachability requires the AMD Display Core HDCP path; published evidence establishes four overruns but no reliable privilege gain or code execution.

CVSS severity7.8
High
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Array-index validation failure in affected Linux kernels allows local users to trigger memory overruns during AMD HDCP handling. The hdcp_ddc.c read and write paths accept MOD_HDCP_MESSAGE_ID_INVALID (-1) as msg_id and use it to index message tables without first rejecting it. Reachability requires the AMD Display Core HDCP path; published evidence establishes four overruns but no reliable privilege gain or code execution.

The record

CVE
CVE-2024-42121
Published
Jul 30, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-129
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 30, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.15
  2. Affected versionversion=4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c <59d99deb330af206a4541db0c4da8f73880fba03
  3. Affected versionversion=4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c <9933eca6ada0cd612e19522e7a319bcef464c0eb
  4. Affected versionversion=4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c <a31ea49dc8064a557565725cf045944307476a6e
  5. Affected versionversion=4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c <ae91ffbc8b8d942e3e7f188728cad557b7ed5ee4
  6. Affected versionversion=4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c <b5b8837d066cc182ff69fb5629ad32ade5484567
  7. Affected versionversion=4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c <fbb0701af9734cff13917a4b98b5ee9da2fde48d

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.15; version=4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c <59d99deb330af206a4541db0c4da8f73880fba03; version=4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c <9933eca6ada0cd612e19522e7a319bcef464c0eb; version=4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c <a31ea49dc8064a557565725cf045944307476a6e; version=4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c <ae91ffbc8b8d942e3e7f188728cad557b7ed5ee4; version=4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c <b5b8837d066cc182ff69fb5629ad32ade5484567; version=4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c <fbb0701af9734cff13917a4b98b5ee9da2fde48d

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-129Improper Validation of Array Index

Public exploit references

No public exploit references are available in this record.

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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