CVE-2026-71225

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

MEDIUM
6.5
CVSS Score
Published: August 5, 2026 at 12:16 PM UTC
Updated: October 22, 2026 at 09:17 PM UTC
5 products affected across 3 vendorsEnterprise LinuxOpenShift Container PlatformHardened Images

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Vendor states this is fixed in 0:1.4.0-2.el9_6.1 (unaffected)
Vendor states this is fixed in 0:1.4.0-3.el8_10 (unaffected)
Vendor states this is fixed in 0:1.4.0-3.el9_8 (unaffected)
Vendor states this is fixed in 0:1.5.0-6.el10_0 (unaffected)
Vendor states this is fixed in 0:1.5.1-1.el10_2 (unaffected)
All versions1
Vendor states this is fixed in 1.5.1-0.1.hum1 (unaffected)
0.10.1 ≤ v < 1.5.1
Affected range stops below 1.5.1, so it looks safe — our inference, not a vendor statement
Affected range stops below 1.5.1, so it looks safe — our inference, not a vendor statement

References (8)

VDB Entryx_refsource_REDHATVendor Advisory
Source: cverecord
https://access.redhat.com/security/cve/CVE-2026-71225
Issue Trackingx_refsource_REDHATExploitVendor Advisory
Source: cverecord
https://bugzilla.redhat.com/show_bug.cgi?id=2462011
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:56985
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:67266
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:67265
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:67267
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:69285
Vendor Advisoryx_refsource_REDHAT
Source: cverecord
https://access.redhat.com/errata/RHSA-2026:87712

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.5MEDIUMredhat
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-330

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