CVE-2024-36931

Kernel-buffer over-read via unterminated CIO input

Published May 30, 2024 · Updated May 11, 2026

An out-of-bounds read in affected Linux 5.13 through 6.9-rc6 kernels allows local users to over-read an s390 CIO kernel buffer. The CIO debugfs injection write handler copies the supplied length into an equal-sized buffer without a trailing NUL, then passes that buffer to sscanf. Reachability requires local permission to write the CIO injection debugfs file, with adjacent kernel-memory disclosure or a kernel crash as bounded consequences.

CVSS severity7.1
High
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

An out-of-bounds read in affected Linux 5.13 through 6.9-rc6 kernels allows local users to over-read an s390 CIO kernel buffer. The CIO debugfs injection write handler copies the supplied length into an equal-sized buffer without a trailing NUL, then passes that buffer to sscanf. Reachability requires local permission to write the CIO injection debugfs file, with adjacent kernel-memory disclosure or a kernel crash as bounded consequences.

The record

CVE
CVE-2024-36931
Published
May 30, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-125
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 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=5.13
  2. Affected versionversion=a4f17cc726712a52122ad38540bc3ff3a052d1a4 <06759ebaf75c19c87b2453a5e130e9e61e9b5d65
  3. Affected versionversion=a4f17cc726712a52122ad38540bc3ff3a052d1a4 <10452edd175fcc4fd0f5ac782ed2a002e3e5d65c
  4. Affected versionversion=a4f17cc726712a52122ad38540bc3ff3a052d1a4 <84b38f48836662c4bfae646c014f4e981e16a2b2
  5. Affected versionversion=a4f17cc726712a52122ad38540bc3ff3a052d1a4 <c9d48ce163305595ae20aee27774192476d5e6a5
  6. Affected versionversion=a4f17cc726712a52122ad38540bc3ff3a052d1a4 <da7c622cddd4fe36be69ca61e8c42e43cde94784

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.13; version=a4f17cc726712a52122ad38540bc3ff3a052d1a4 <06759ebaf75c19c87b2453a5e130e9e61e9b5d65; version=a4f17cc726712a52122ad38540bc3ff3a052d1a4 <10452edd175fcc4fd0f5ac782ed2a002e3e5d65c; version=a4f17cc726712a52122ad38540bc3ff3a052d1a4 <84b38f48836662c4bfae646c014f4e981e16a2b2; version=a4f17cc726712a52122ad38540bc3ff3a052d1a4 <c9d48ce163305595ae20aee27774192476d5e6a5; version=a4f17cc726712a52122ad38540bc3ff3a052d1a4 <da7c622cddd4fe36be69ca61e8c42e43cde94784

Published CVSS scores

7.1NISTCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-125Out-of-bounds Read

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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