Libkcapi: iv reuse in libkcapi one-shot symmetric cipher chunking causes cipher state reset across chunk boundaries (CVE-2026-71225) | HOL Guard CVE

Medium · CVSS 6.5CVE-2026-71225

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

Answer in brief

CVE-2026-71225 records a Medium severity (CVSS 6.5) vulnerability in Libkcapi: iv reuse in libkcapi one-shot symmetric cipher chunking causes cipher state reset across chunk boundaries. The current sources do not mark it as known exploited. The current feed maps Stephan Muelle/libkcapi (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 5, 2026Updated Sep 14, 2026Source checked Sep 19, 2026First seen by HOL Aug 5, 2026Material review Sep 14, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 6.5
Exploitation: Not marked as known exploited
Affected software: 7 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 6.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Stephan Muelle/libkcapi (generic). Check affected ranges and fixed versions before updating.

Affected products and reported versions
Product	Affected versions	Fixed versions
cpe:2.3:a:redhat:hardened_images:-:::::::*	Not reported	Not reported
cpe:2.3:a:redhat:openshift_container_platform:4.0:::::::*	Not reported	Not reported
cpe:2.3:a:smuellerdd:libkcapi::::::::	Not reported	Not reported
cpe:2.3:o:redhat:enterprise_linux:10.0:::::::*	Not reported	Not reported
cpe:2.3:o:redhat:enterprise_linux:8.0:::::::*	Not reported	Not reported
cpe:2.3:o:redhat:enterprise_linux:9.0:::::::*	Not reported	Not reported

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Stephan Muelle/libkcapigeneric	>=0.10.1 <1.5.1	1.5.1

Recommended response

Check inventory. Check lockfiles and deployed manifests for Stephan Muelle/libkcapi.
Review the reported fix. Update Stephan Muelle/libkcapi to 1.5.1 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 14, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 5, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.