CVE-2026-71225
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.
Executive briefing
The source record describes: 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. The practical risk depends on whether an affected product/version is present, reachable and configured in an exploitable way. Review the affected-product evidence and linked vendor advisories before assigning exposure status.
Evidence confidence: Moderate Evidence-derived, not an exploitability verdict
Severity & attack characteristics
CVSS vector:CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
Technical explanation & impact
The technical mechanism is not expanded beyond the source description unless a referenced advisory supplies additional evidence. Read the linked vendor/CERT advisories for root-cause detail.
Potential impact must be interpreted from the published CVSS impact metrics and the affected component. A CVSS impact score is not proof that a particular asset is exploitable.
Weakness classification
CWE-330Affected products and versions
Products below are parsed from NVD vulnerable CPE configuration entries. Version boundaries are shown as published; verify applicability with the vendor.
| Vendor | Product | Version evidence |
|---|---|---|
| redhat | hardened_images | Version not specified in CPE |
| redhat | openshift_container_platform | CPE version 4.0 |
| smuellerdd | libkcapi | from (inclusive) 0.10.1; before 1.5.1 |
| redhat | enterprise_linux | CPE version 8.0 · CPE version 9.0 · CPE version 10.0 |
Remediation & validation
- Identify exposure by comparing the affected product and version ranges with your asset inventory, SBOM and externally exposed services.
- Review the linked vendor security advisory or patch notes. Upgrade to a vendor-confirmed fixed release; do not infer a fixed version from the CVE description.
- Until patched, consider restricting network access or disabling the affected feature where operationally safe. These are temporary controls, not a substitute for a vendor fix.
- Validate the remediation with a version check and vulnerability rescan, then retain change evidence.
No fixed version is displayed unless it is explicitly established by a vendor advisory. Follow the vendor's release notes for exact product and branch applicability.
Vendor advisories, patches & exploit references
- https://access.redhat.com/errata/RHSA-2026:56985 VENDOR secalert@redhat.com
- https://access.redhat.com/errata/RHSA-2026:67265 VENDOR secalert@redhat.com
- https://access.redhat.com/errata/RHSA-2026:67266 VENDOR secalert@redhat.com
- https://access.redhat.com/errata/RHSA-2026:67267 VENDOR secalert@redhat.com
- https://access.redhat.com/errata/RHSA-2026:69285 VENDOR secalert@redhat.com
- https://access.redhat.com/errata/RHSA-2026:87712 VENDOR secalert@redhat.com
- https://access.redhat.com/security/cve/CVE-2026-71225 ADVISORY secalert@redhat.com
- https://bugzilla.redhat.com/show_bug.cgi?id=2462011 EXPLOIT secalert@redhat.com