CVE-2026-43406 (CVSS 9.1)

Description

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.

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CVSS v3.1 Score

9.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

EPSS — Exploit Prediction

0.0007

Probability of exploitation

0.22%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/035867ae6f18df0aeedb2a57a5b74091bd4e3fe8 https://git.kernel.org/stable/c/50156622eb0888e62541d715a98584480a1bc7cb https://git.kernel.org/stable/c/69fb5d91bba44ecf7eb80530b85fa4fb028921d5 https://git.kernel.org/stable/c/69fe5af33fa3806f398d21c081d73c66e5523bc2 https://git.kernel.org/stable/c/75582aaa580c11aed4c7731cad6b068b700e7efb https://git.kernel.org/stable/c/76ccf21a12c5f6d6790bc32c7da82446d877b2f4 https://git.kernel.org/stable/c/dbd857a9e1e33ea71eaf3e211877027e533770d1

Frequently Asked Questions

What is CVE-2026-43406? +

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. It has a CVSS v3.1 base score of 9.1 (CRITICAL).

How severe is CVE-2026-43406? +

CVE-2026-43406 has a CVSS v3.1 score of 9.1 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0007, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-43406? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

CVE-2026-43406