CVE-2026-43406Network attack vector

Memory disclosure and storage disruption via undersized frame

Published May 8, 2026 · Updated May 8, 2026

Out-of-bounds read in Linux Kernel libceph allows remote attackers to expose kernel memory and disrupt Ceph storage via malformed msgr2 frames. process_message_header() decodes a ceph_msg_header2 from a control segment without first ensuring that the complete structure is present. An unauthenticated Ceph peer can trigger the flaw before credential verification against a configured or reconnecting client; repeated frames can deny kernel Ceph storage access.

CVSS severity9.1
Critical
EPSS probability0.50%
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 libceph allows remote attackers to expose kernel memory and disrupt Ceph storage via malformed msgr2 frames. process_message_header() decodes a ceph_msg_header2 from a control segment without first ensuring that the complete structure is present. An unauthenticated Ceph peer can trigger the flaw before credential verification against a configured or reconnecting client; repeated frames can deny kernel Ceph storage access.

The record

CVE
CVE-2026-43406
Published
May 8, 2026
Updated
May 8, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-125, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 8, 2026CVE publishedPublication date reported by the CVE source.
  2. May 8, 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <035867ae6f18df0aeedb2a57a5b74091bd4e3fe8
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <50156622eb0888e62541d715a98584480a1bc7cb
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <69fb5d91bba44ecf7eb80530b85fa4fb028921d5
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <69fe5af33fa3806f398d21c081d73c66e5523bc2
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <75582aaa580c11aed4c7731cad6b068b700e7efb
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <76ccf21a12c5f6d6790bc32c7da82446d877b2f4
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <dbd857a9e1e33ea71eaf3e211877027e533770d1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <035867ae6f18df0aeedb2a57a5b74091bd4e3fe8; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <50156622eb0888e62541d715a98584480a1bc7cb; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <69fb5d91bba44ecf7eb80530b85fa4fb028921d5; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <69fe5af33fa3806f398d21c081d73c66e5523bc2; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <75582aaa580c11aed4c7731cad6b068b700e7efb; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <76ccf21a12c5f6d6790bc32c7da82446d877b2f4; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <dbd857a9e1e33ea71eaf3e211877027e533770d1

Published CVSS scores

9.1Linux kernel CNACVSS:3.1/AV:N/AC:L/PR:N/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.

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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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1499.004Application or System Exploitation

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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