---
id: CVE-2026-71225
title: A flaw was found in libkcapi
summary: >-
  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 Vec…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N'
cwe:
  - CWE-330
vendor: redhat
product: hardened_images
affected:
  - hardened_images
  - openshift_container_platform = 4.0
  - 'libkcapi >= 0.10.1, < 1.5.1'
  - enterprise_linux = 8.0
  - enterprise_linux = 9.0
  - enterprise_linux = 10.0
patched:
  - libkcapi 1.5.1
published: '2026-08-05'
updated: '2026-09-21'
sourceUpdated: '2026-09-21T13:17:09.720'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-71225'
references:
  - url: 'https://access.redhat.com/errata/RHSA-2026:56985'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:67265'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:67266'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:67267'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:69285'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/security/cve/CVE-2026-71225'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2462011'
    label: secalert@redhat.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-71225.json
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-71225'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-71225'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-08-05T14:20:51.007088Z'
epss: 0.00521
epssPercentile: 0.41708
ingestedAt: '2026-08-10T09:39:29.627Z'
---

## Overview

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 internal data chunk. A remote attacker could potentially exploit this by making an application that uses libkcapi process specially crafted large inputs. This can lead to a significant weakening of data confidentiality, as the repeated IV use can expose relationships in encrypted plaintext, and may also affect data integrity by causing incorrect cryptographic processing.

## Affected

- `hardened_images`
- `openshift_container_platform = 4.0`
- `libkcapi >= 0.10.1, < 1.5.1`
- `enterprise_linux = 8.0`
- `enterprise_linux = 9.0`
- `enterprise_linux = 10.0`

## Remediation

Upgrade past the affected range:

- `libkcapi 1.5.1`

## Vendor advisories

- **RHSA-2026:67267** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 10) · released 2026-09-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:67267)
- **RHSA-2026:67266** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 8) · released 2026-09-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:67266)
- **RHSA-2026:67265** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 9) · released 2026-09-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:67265)
- **RHSA-2026:56985** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-08-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:56985)
- **Red Hat VEX** · Moderate · affected: Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat OpenShift Container Platform 4 · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-71225.json)
- **RHSA-2026:69285** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS EUS (v. 10.0) · released 2026-09-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:69285)