CVE-2026-71227: Libkcapi: infinite loop denial of service in libkcapi _kcapi_aio_read_all() due to unhandled io_getevents() timeout return

Severity: medium (CVSS 5.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-08-05 · updated 2026-10-22
Weakness: CWE-835

Description

A flaw was found in libkcapi. A local attacker can influence an application that uses the Asynchronous Input/Output (AIO) interface. By reusing an AIO-enabled handle after a prior completion error, the _kcapi_aio_read_all() function can enter a non-terminating wait loop. This can lead to a persistent denial of service, making the affected application or thread unresponsive.

Affected products

Red Hat Enterprise Linux: 8.0, 9.0, 10.0
RedHat Hardened Images: all versions
Red Hat OpenShift Container Platform 4.18: 4.0
smuellerDD Libkcapi: from 0.12.0 before 1.5.1 — fixed in 1.5.1

How to fix

Upgrade to a fixed version: smuellerDD Libkcapi 1.5.1. Check the vendor advisory for mitigations.

References

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