Microsoft Security Response Center guidance
Vendor revision: Aug 23, 2026CBL-Mariner Releases
Vendor-listed releases
- 1.5.1-1
Vulnerability intelligence
CVE-2026-71225 and is rated Medium severity with a CVSS score of 6.5. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
CBL-Mariner Releases
Vendor-listed releases
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.
Source: NVD