Bug 2468251 (CVE-2026-43406)

Summary: CVE-2026-43406 kernel: libceph: prevent potential out-of-bounds reads in process_message_header()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in libceph in the Linux kernel. A remote attacker could exploit this vulnerability by sending a maliciously crafted message frame. This manipulation, either by corrupting the control segment length or disguising a different frame as a message frame, can cause out-of-bounds reads during message header processing. Such an issue may lead to information disclosure or system instability.
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Description OSIDB Bzimport 2026-05-08 15:07:05 UTC 
In the Linux kernel, the following vulnerability has been resolved:

libceph: prevent potential out-of-bounds reads in process_message_header()

If the message frame is (maliciously) corrupted in a way that the
length of the control segment ends up being less than the size of the
message header or a different frame is made to look like a message
frame, out-of-bounds reads may ensue in process_message_header().

Perform an explicit bounds check before decoding the message header.
Comment 1 Keith Grant 2026-05-08 22:25:35 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026050842-CVE-2026-43406-84a2@gregkh/T