CVE-2026-43406
CVE-2026-43406 is a critical-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.
Key facts
- Severity: Critical (CVSS 3.x base score 9.1)
- EPSS exploit prediction: 1% (39th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-28712
- Weakness: CWE-125
- Affected product: Linux Linux Kernel
- Published:
- Last modified:
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.
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.
- How severe is CVE-2026-43406?
- CVE-2026-43406 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
- Is CVE-2026-43406 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (39th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2026-43406?
- CVE-2026-43406 primarily affects Linux Linux Kernel. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2026-43406?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
- Does CVE-2026-43406 have an EU (EUVD) identifier?
- Yes. CVE-2026-43406 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-28712.
- When was CVE-2026-43406 published?
- CVE-2026-43406 was published on 2026-05-08 and last updated on 2026-06-17.
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
Affected products (4)
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*
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