CVE-2026-71225
Libkcapi: iv reuse in libkcapi one-shot symmetric cipher chunking causes cipher state reset across chunk boundaries
Record summary
CVE-2026-71225 has a selected CVSS score of 6.5 (medium).
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.
Exploitation context
CISA SSVC decision
CISA Coordinator · SSVC 2.0.3 · Evaluated Aug 5, 2026 · Source: CVE List
Affected products and versions
6| Product | Source | Version range | Status |
|---|---|---|---|
Default status: affected | CVE List | Version data not supplied | |
Default status: affected | CVE List | Version data not supplied | |
Default status: affected | CVE List | Version data not supplied | |
Default status: affected | CVE List | Version data not supplied | |
Default status: affected | CVE List | Version data not supplied | |
libkcapiBrowse Stephan Muelle / libkcapiDefault status: unaffected | CVE List | 0.10.1 to < 1.5.1 | affected |