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
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Stephan Muelle | libkcapi | 0.12.0 – < 1.5.1 | 1.5.1 |
| Red Hat | Red Hat Enterprise Linux 10 | — | — |
| Red Hat | Red Hat Enterprise Linux 10.0 Extended Update Support | — | — |
| Red Hat | Red Hat Enterprise Linux 8 | — | — |
| Red Hat | Red Hat Enterprise Linux 9 | — | — |
| Red Hat | Red Hat Enterprise Linux 9.6 Extended Update Support | — | — |
| Red Hat | Red Hat Hardened Images | — | — |
| Red Hat | Red Hat OpenShift Container Platform 4 | — | — |
| Red Hat | Red Hat OpenShift Container Platform 5 | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | libkcapi | 1.5.1-1 | — |
| Debian 13 | libkcapi | No fix yet | — |
| Debian 12 | libkcapi | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | libkcapi | No fix yet | — |
| Ubuntu 26.04 LTS | libkcapi | No fix yet | — |
| Ubuntu 24.04 LTS | libkcapi | No fix yet | — |
| Ubuntu 22.04 LTS | libkcapi | No fix yet | — |
| Ubuntu 20.04 LTS | libkcapi | No fix yet | — |
Show 9 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | libkcapi | No fix yet | — |
| Ubuntu Pro FIPS 20.04 LTS | libkcapi | No fix yet | — |
| Ubuntu Pro FIPS 18.04 LTS | libkcapi | No fix yet | — |
| Ubuntu Pro FIPS 16.04 LTS | libkcapi | No fix yet | — |
| Ubuntu Pro FIPS-updates 22.04 LTS | libkcapi | No fix yet | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | libkcapi | No fix yet | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | libkcapi | No fix yet | — |
| Ubuntu Pro FIPS-updates 16.04 LTS | libkcapi | No fix yet | — |
| Ubuntu Pro FIPS-preview 22.04 LTS | libkcapi | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | libkcapi +2 | 1.5.1-1.el10_2 | RHSA-2026:67267 |
| RHEL 9 | libkcapi +1 | 1.4.0-3.el9_8 | RHSA-2026:67265 |
| RHEL 8 | libkcapi +1 | 1.4.0-3.el8_10 | RHSA-2026:67266 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10.0 EUS | libkcapi | 1.5.0-6.el10_0 | RHSA-2026:69285 |
| RHEL 9.6 EUS | libkcapi +1 | 1.4.0-2.el9_6.1 | RHSA-2026:87712 |
| Red Hat Hardened Images 1 | libkcapi +7 | 1.5.1-0.1.hum1 | RHSA-2026:56985 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | libkcapi +2 | 1.5.1-1.el10_2 | ALSA-2026:67267 |
| AlmaLinux 9 | libkcapi +1 | 1.4.0-3.el9_8 | ALSA-2026:67265 |
| AlmaLinux 8 | libkcapi +1 | 1.4.0-3.el8_10 | ALSA-2026:67266 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | libkcapi | 1.5.1-1.el10_2 | RLSA-2026:67267 |
| Rocky Linux 9 | libkcapi | 1.4.0-3.el9_8 | RLSA-2026:67265 |
| Rocky Linux 8 | libkcapi | 1.4.0-3.el8_10 | RLSA-2026:67266 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | libkcapi | 1.5.1-r0 | — |
| Alpine v3.23 | libkcapi | 1.5.1-r0 | — |
| Alpine v3.22 | libkcapi | 1.5.1-r0 | — |
| Alpine v3.21 | libkcapi | 1.5.1-r0 | — |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | libkcapi | 1.5.1-1 | — |
Advisories 13
- RHSA-2026:87712 Red Hat Security Advisory: libkcapi security update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- WID-SEC-2026-3322 Red Hat Enterprise Linux (libkcapi): Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 9, 2026
- ALSA-2026:67265 Moderate: libkcapi security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:67267 Moderate: libkcapi security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:67266 Moderate: libkcapi security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2026:56985 Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update Red Hat Security Advisories (RHSA) · Oct 6, 2026
- RHSA-2026:69285 Red Hat Security Advisory: libkcapi security update Red Hat Security Advisories (RHSA) · Sep 22, 2026
- RHSA-2026:67267 Red Hat Security Advisory: libkcapi security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Sep 22, 2026
- RHSA-2026:67265 Red Hat Security Advisory: libkcapi security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Sep 22, 2026
- RHSA-2026:67266 Red Hat Security Advisory: libkcapi security update Red Hat Security Advisories (RHSA) · Sep 22, 2026
- RLSA-2026:67265 Moderate: libkcapi security, bug fix, and enhancement update Rocky Linux Security Advisories · Sep 15, 2026
- RLSA-2026:67267 Moderate: libkcapi security, bug fix, and enhancement update Rocky Linux Security Advisories · Sep 15, 2026
- RLSA-2026:67266 Moderate: libkcapi security update Rocky Linux Security Advisories · Sep 15, 2026
References
- RHSA-2026:56985 vendor-advisory
- RHSA-2026:67265 vendor-advisory
- RHSA-2026:67266 vendor-advisory
- RHSA-2026:67267 vendor-advisory
- RHSA-2026:69285 vendor-advisory
- RHSA-2026:87712 vendor-advisory
- https://access.redhat.com/security/cve/CVE-2026-71227 vdb-entry
- RHBZ#2462867 issue-tracking