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Public vulnerability disclosure

CVE-2026-71227

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

publishedCWE-835

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.

Investigate in Cyber JSONMarkdown
Technical severity5.1 mediumCVSS 3.1 · CNA: redhat
Published2026-08-05Source updated 2026-11-02
Collected2026-11-022 attributed sources

Fixes and workarounds

Workaround

To mitigate this issue, applications should avoid initializing `libkcapi` handles with `KCAPI_INIT_AIO` if AIO functionality is not strictly required. If AIO must be used, applications should destroy and reinitialize `libkcapi` handles after any AIO completion error, rather than reusing them for subsequent AIO operations.

Source: CNA: redhat

Affected products and versions

ProductVersionsAuthority
libkcapi
Stephan Muelle 		≥ 0.12.0; < 1.5.1 (affected, semver)
Other versions: unaffected 		CNA: redhat
Red Hat Enterprise Linux 10
Red Hat
libkcapi
https://access.redhat.com/downloads/content/package-browser/ 		≥ 0:1.5.1-1.el10_2; < * (unaffected, rpm)
Other versions: affected 		CNA: redhat
Red Hat Enterprise Linux 10.0 Extended Update Support
Red Hat
libkcapi
https://access.redhat.com/downloads/content/package-browser/ 		≥ 0:1.5.0-6.el10_0; < * (unaffected, rpm)
Other versions: affected 		CNA: redhat
Red Hat Enterprise Linux 8
Red Hat
libkcapi
https://access.redhat.com/downloads/content/package-browser/ 		≥ 0:1.4.0-3.el8_10; < * (unaffected, rpm)
Other versions: affected 		CNA: redhat
Red Hat Enterprise Linux 9
Red Hat
libkcapi
https://access.redhat.com/downloads/content/package-browser/ 		≥ 0:1.4.0-3.el9_8; < * (unaffected, rpm)
Other versions: affected 		CNA: redhat
Red Hat Enterprise Linux 9.6 Extended Update Support
Red Hat
libkcapi
https://access.redhat.com/downloads/content/package-browser/ 		≥ 0:1.4.0-2.el9_6.1; < * (unaffected, rpm)
Other versions: affected 		CNA: redhat
Red Hat Hardened Images
Red Hat
libkcapi-main
https://catalog.redhat.com/software/containers/ 		≥ 1.5.1-0.1.hum1; < * (unaffected, rpm)
Other versions: affected 		CNA: redhat
Red Hat OpenShift Container Platform 4
Red Hat
openshift/ose-rhel-coreos-8
https://access.redhat.com/downloads/content/package-browser/ 		Range not reported
Other versions: affected 		CNA: redhat
Red Hat OpenShift Container Platform 4
Red Hat
openshift/ose-rhel-coreos-9
https://access.redhat.com/downloads/content/package-browser/ 		Range not reported
Other versions: affected 		CNA: redhat
Red Hat OpenShift Container Platform 5
Red Hat
openshift/ose-rhel-coreos-9
https://access.redhat.com/downloads/content/package-browser/ 		Range not reported
Other versions: affected 		CNA: redhat

Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.

CVSS assessments

Version / scoreVectorAuthority
3.1 / 5.1
medium		 CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:HCNA: redhat

Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

References