Medium

Libkcapi: iv reuse in libkcapi one-shot symmetric cipher chunking causes cipher state reset across chunk boundaries

Type: advisorySource: Official CVE List1 source record

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.

Announced 5 Aug 2026Source revision 1

Original source ↗

CVE-2026-71225

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-71225

libkcapi

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat Enterprise Linux 10

Source reference: /containers/cna/affected/1/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat Enterprise Linux 10.0 Extended Update Support

Source reference: /containers/cna/affected/2/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat Enterprise Linux 8

Source reference: /containers/cna/affected/3/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat Enterprise Linux 9

Source reference: /containers/cna/affected/4/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat Enterprise Linux 9.6 Extended Update Support

Source reference: /containers/cna/affected/5/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat Hardened Images

Source reference: /containers/cna/affected/6/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat OpenShift Container Platform 4

Source reference: /containers/cna/affected/7/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Red Hat OpenShift Container Platform 4

Source reference: /containers/cna/affected/8/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://github.com/smuellerDD/libkcapi",
    "vendor": "Stephan Muelle",
    "product": "libkcapi",
    "versions": [
      {
        "status": "affected",
        "version": "0.10.1",
        "lessThan": "1.5.1",
        "versionType": "semver"
      }
    ],
    "defaultStatus": "unaffected"
  },
  {
    "cpes": [
      "cpe:/o:redhat:enterprise_linux:10.2"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Enterprise Linux 10",
    "versions": [
      {
        "status": "unaffected",
        "version": "0:1.5.1-1.el10_2",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "libkcapi",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/o:redhat:enterprise_linux_eus:10.0"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Enterprise Linux 10.0 Extended Update Support",
    "versions": [
      {
        "status": "unaffected",
        "version": "0:1.5.0-6.el10_0",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "libkcapi",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/o:redhat:enterprise_linux:8::baseos"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Enterprise Linux 8",
    "versions": [
      {
        "status": "unaffected",
        "version": "0:1.4.0-3.el8_10",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "libkcapi",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/o:redhat:enterprise_linux:9::baseos"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Enterprise Linux 9",
    "versions": [
      {
        "status": "unaffected",
        "version": "0:1.4.0-3.el9_8",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "libkcapi",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/o:redhat:rhel_eus:9.6::baseos"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Enterprise Linux 9.6 Extended Update Support",
    "versions": [
      {
        "status": "unaffected",
        "version": "0:1.4.0-2.el9_6.1",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "libkcapi",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/a:redhat:hummingbird:1"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat Hardened Images",
    "versions": [
      {
        "status": "unaffected",
        "version": "1.5.1-0.1.hum1",
        "lessThan": "*",
        "versionType": "rpm"
      }
    ],
    "packageName": "libkcapi-main",
    "collectionURL": "https://catalog.redhat.com/software/containers/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/a:redhat:openshift:4"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat OpenShift Container Platform 4",
    "packageName": "openshift/ose-rhel-coreos-8",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "affected"
  },
  {
    "cpes": [
      "cpe:/a:redhat:openshift:4"
    ],
    "vendor": "Red Hat",
    "product": "Red Hat OpenShift Container Platform 4",
    "packageName": "openshift/ose-rhel-coreos-9",
    "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
    "defaultStatus": "affected"
  }
]

Related CVEs: CVE-2026-71225
Source reference: /cveMetadata/cveId

Publisher severity

medium

Source reference: /containers/cna/metrics

Event: #52392 · Revision 1
Added to Heist Feed: Sun, 25 Oct 2026 14:44:10 GMT
Publisher date: Wed, 05 Aug 2026 12:16:52 GMT

Read the original announcement