CVE-2026-43366: Linux kernel · Race Condition
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in f3fb54e7a8b4aadcc2836ee463eec8c88709b8aa : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:30 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in f3fb54e7a8b4aadcc2836ee463eec8c88709b8aa, c2c185be5c85d37215397c8e8781abf0a69bec1f, a7b33671e418fca507feebd1d56e7f4952a4b25c +3
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 8 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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AI-suggested
A fix for this vulnerability is available and has been applied in specific Linux kernel commits. Users and administrators should update affected Linux kernel versions to the patched releases containing these fixes. Since this is a kernel-level issue, applying the official patches or upgrading to a fixed kernel version is the recommended mitigation.
Description
CVE-2026-43366 is a high-severity vulnerability in the Linux kernel's io_uring subsystem affecting version 5.19. It involves improper checks during buffer recycling where a legacy buffer list may be incorrectly handled if it has been upgraded to a ring-provided type. This flaw could lead to critical impacts on confidentiality, integrity, and availability.
References
- git.kernel.org/stable/c/a7b33671e418fca507feebd1d56e7f4952a4b25c (opens in a new tab)
- git.kernel.org/stable/c/439a6728ec4641ffad1ca796622c19bc525e570f (opens in a new tab)
- git.kernel.org/stable/c/f3fb54e7a8b4aadcc2836ee463eec8c88709b8aa (opens in a new tab)
- git.kernel.org/stable/c/50ad880db3013c6fee0ef13781762a39e2e7ef83 (opens in a new tab)
- git.kernel.org/stable/c/97b57f69fee1b61b41acbf37e7720cac9d389fa4 (opens in a new tab)
- git.kernel.org/stable/c/c2c185be5c85d37215397c8e8781abf0a69bec1f (opens in a new tab)