CVE-2026-71225

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

State
Published
Severity
6.5 Medium
Published
Aug 5, 2026
Updated
Nov 2, 2026
Reserved
Aug 5, 2026

Read the record on cve.org

Description

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.

Scores

CVSSScoreVectorSource
3.16.5 MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:Nredhat

Weaknesses

  • CWE-330 Use of Insufficiently Random Values

Affected Products

ProductVersions
libkcapiStephan Muelle
  • 0.10.1 to before 1.5.1Affected
Red Hat Enterprise Linux 10Red Hat
  • 0:1.5.1-1.el10_2 and laterNot affected
Red Hat Enterprise Linux 10.0 Extended Update SupportRed Hat
  • 0:1.5.0-6.el10_0 and laterNot affected
Red Hat Enterprise Linux 8Red Hat
  • 0:1.4.0-3.el8_10 and laterNot affected
Red Hat Enterprise Linux 9Red Hat
  • 0:1.4.0-3.el9_8 and laterNot affected
Red Hat Enterprise Linux 9.6 Extended Update SupportRed Hat
  • 0:1.4.0-2.el9_6.1 and laterNot affected
Red Hat Hardened ImagesRed Hat
  • 1.5.1-0.1.hum1 and laterNot affected
Red Hat OpenShift Container Platform 4Red Hat
    Red Hat OpenShift Container Platform 4Red Hat
      Red Hat OpenShift Container Platform 5Red Hat

        References

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