Summary
libkcapi allows user-space to access the Linux kernel crypto API. This library uses the netlink interface and exports easy to use APIs so that a developer does not need to consider the low-level netlink interface handling. The library does not implement any cipher algorithms. All consumer requests are sent to the kernel for processing. Results from the kernel crypto API are returned to the consumer via the library API. The kernel interface and therefore this library can be used by unprivileged processes.
Security Fix(es):
* libkcapi: IV reuse in libkcapi one-shot symmetric cipher chunking causes cipher state reset across chunk boundaries (CVE-2026-71225)
* libkcapi: Memory corruption via uncanceled AIO requests on error in libkcapi's one-shot AIO path (CVE-2026-71226)
* libkcapi: Infinite loop denial of service in libkcapi _kcapi_aio_read_all() due to unhandled io_getevents() timeout return (CVE-2026-71227)
Bug Fix(es) and Enhancement(s):
* libkcapi: rebase to 1.5.1 [almalinux-10.2.z] (JIRA:AlmaLinux-242508)
* libkcapi: AEAD Decrypt Auth Check Skipped for Zero-Length Input in `kcapi-enc` [almalinux-10.2.z] (JIRA:AlmaLinux-242665)
For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
Fixed packages 3
| Release | Package | Fixed in |
|---|---|---|
| AlmaLinux · 10 | libkcapi | 1.5.1-1.el10_2 |
| AlmaLinux · 10 | libkcapi-hasher | 1.5.1-1.el10_2 |
| AlmaLinux · 10 | libkcapi-hmaccalc | 1.5.1-1.el10_2 |
Vulnerabilities 3
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High 7.3
Libkcapi: memory corruption via uncanceled aio requests on error in libkcapi's one-shot aio path
Memory Corruption via Uncanceled AIO Requests on Error: libkcapi's one-shot AIO path can return an error before all submitted IOCBs are drained, allowing later kernel writes into caller-owned output buffers.
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Medium 6.5
Libkcapi: iv reuse in libkcapi one-shot symmetric cipher chunking causes cipher state reset across chunk boundaries
A flaw was found in libkcapi. When performing one-shot symmetric cipher operations on large inputs (over 64 KiB) in stateful modes such as Counter (CTR) or Cipher Block Chaining (CBC), the library improperly reuses the Initialization Vector (IV) for each inte…
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Medium 5.1
Libkcapi: infinite loop denial of service in libkcapi _kcapi_aio_read_all() due to unhandled io_getevents() timeout return
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-terminatin…
References
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report
https://access.redhat.com/security/cve/CVE-2026-71225
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report
https://access.redhat.com/security/cve/CVE-2026-71226
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report
https://access.redhat.com/security/cve/CVE-2026-71227
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report
https://bugzilla.redhat.com/2462011
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report
https://bugzilla.redhat.com/2462114
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report
https://bugzilla.redhat.com/2462867
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advisory
https://errata.almalinux.org/10/ALSA-2026-67267.html