CVE-2026-71225
MediumCVSS 6.5Exploitation Probability (EPSS)
Low risk24th percentile - higher than 24% of all known CVEs
Summary
In libkcapi, when performing one-shot symmetric cipher operations on large inputs (over 64 KiB) in stateful modes like CTR or CBC, the library improperly reuses the IV for each internal chunk. A remote attacker could exploit this, leading to weakened data confidentiality and potential integrity issues.
Risk Assessment
Repeated IV use can expose relationships in encrypted plaintext, potentially leading to data decryption or integrity compromise.
Recommendation
Update libkcapi to a patched version. Avoid processing very large inputs in stateful modes if possible.
Other vulnerabilities in libkcapi
See all- CVE-2026-71227Medium
A flaw in libkcapi allows a local attacker to influence an application using the AIO interface. Reusing an AIO-enabled handle after a prior completion error can cause _kcapi_aio_read_all() to enter a non-terminating wait loop, leading to persistent denial of service.
- CVE-2026-71226High
In libkcapi, the one-shot AIO path can return an error before all IOCBs are drained, allowing the kernel to later write into caller-owned output buffers, causing memory corruption.
Original NVD description (English source)
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.