Use After Free Affecting smuellerDD/libkcapi package, versions [,1.5.1)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-UNMANAGED-SMUELLERDDLIBKCAPI-18600604
- published9 Aug 2026
- disclosed5 Aug 2026
- creditUnknown
Introduced: 5 Aug 2026
NewCVE-2026-71226 (opens in a new tab)How to fix?
Upgrade smuellerDD/libkcapi to version 1.5.1 or higher.
Overview
Affected versions of this package are vulnerable to Use After Free in the one-shot Asynchronous I/O process when the KCAPI_INIT_AIO flag is used. An attacker can cause memory corruption by triggering an error after submitting I/O Control Blocks, then freeing or reusing output buffers before all kernel completions are processed, which may result in delayed kernel writes into reallocated or freed memory. This is only exploitable if the application is configured to use the opt-in AIO setup with the KCAPI_INIT_AIO flag enabled.
Workaround
This vulnerability can be mitigated by avoiding initialization with the KCAPI_INIT_AIO flag and preferring synchronous interfaces, or by ensuring that outiov buffers are not freed or reused until all kernel completions have finished.