CVE-2026-43366

Description

In the Linux kernel, the following vulnerability has been resolved: io_uring/kbuf: check if target buffer list is still legacy on recycle There's a gap between when the buffer was grabbed and when it potentially gets recycled, where if the list is empty, someone could've upgraded it to a ring provided type. This can happen if the request is forced via io-wq. The legacy recycling is missing checking if the buffer_list still exists, and if it's of the correct type. Add those checks.

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CVSS v3.1 Score

7.8

HIGH

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

EPSS — Exploit Prediction

0.0001

Probability of exploitation

0.02%

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.

Affected Products

Vendor	Product	Versions
linux	linux_kernel	5.19 — 6.1.167
linux	linux_kernel	6.2 — 6.6.130
linux	linux_kernel	6.7 — 6.12.78
linux	linux_kernel	6.13 — 6.18.19
linux	linux_kernel	6.19 — 6.19.9
linux	linux_kernel	All
linux	linux_kernel	All
linux	linux_kernel	All

References

Advisories & Patches

https://git.kernel.org/stable/c/439a6728ec4641ffad1ca796622c19bc525e570f https://git.kernel.org/stable/c/50ad880db3013c6fee0ef13781762a39e2e7ef83 https://git.kernel.org/stable/c/97b57f69fee1b61b41acbf37e7720cac9d389fa4 https://git.kernel.org/stable/c/a7b33671e418fca507feebd1d56e7f4952a4b25c https://git.kernel.org/stable/c/c2c185be5c85d37215397c8e8781abf0a69bec1f https://git.kernel.org/stable/c/f3fb54e7a8b4aadcc2836ee463eec8c88709b8aa

Frequently Asked Questions

What is CVE-2026-43366? +

In the Linux kernel, the following vulnerability has been resolved: io_uring/kbuf: check if target buffer list is still legacy on recycle There's a gap between when the buffer was grabbed and when it potentially gets recycled, where if the list is empty, someone could've upgraded it to a ring provided type. This can happen if the request is forced via io-wq. The legacy recycling is missing checking if the buffer_list still exists, and if it's of the correct type. Add those checks. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2026-43366? +

CVE-2026-43366 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0001, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-43366? +

CVE-2026-43366 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2026-43366? +

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.

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