CVE-2026-71225
published 2026-08-05CVE-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…
PriorityP342medium6.5CVSS 3.1
AVNACHPRNUINSUCHILAN
EPSS
0.52%
43.4th percentile
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.
Affected
6 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| redhat | enterprise_linux | — | — |
| redhat | enterprise_linux | — | — |
| redhat | enterprise_linux | — | — |
| redhat | openshift_container_platform | — | — |
| smuellerdd | libkcapi | >= 0.10.1 < 1.5.1 | 1.5.1 |
| stephan_muelle | libkcapi | >= 0.10.1 < 1.5.1 | 1.5.1 |
CVSS provenance
nvdv3.16.5MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
vendor_redhat6.5MEDIUM
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Red Hat
libkcapi: IV reuse in libkcapi one-shot symmetric cipher chunking causes cipher state reset across chunk boundaries
vendor_redhat·2026-08-05·CVSS 6.5
CVE-2026-71225 [MEDIUM] CWE-330 libkcapi: IV reuse in libkcapi one-shot symmetric cipher chunking causes cipher state reset across chunk boundaries
libkcapi: IV reuse in libkcapi one-shot symmetric cipher chunking causes cipher state reset across chunk boundaries
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.
Mitigation: To mitigate this issue, applications usin
GHSA
A flaw was found in libkcapi.
ghsa_unreviewed·2026-08-05
CVE-2026-71225 [MEDIUM] CWE-330 A flaw was found in libkcapi.
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.
No detection rules found.
No public exploits indexed.
Bugzilla
CVE-2026-71225 libkcapi: IV reuse in libkcapi one-shot symmetric cipher chunking causes cipher state reset across chunk boundaries [fedora-all]
bugzilla·2026-08-05·CVSS 6.5
CVE-2026-71225 [MEDIUM] CVE-2026-71225 libkcapi: IV reuse in libkcapi one-shot symmetric cipher chunking causes cipher state reset across chunk boundaries [fedora-all]
CVE-2026-71225 libkcapi: IV reuse in libkcapi one-shot symmetric cipher chunking causes cipher state reset across chunk boundaries [fedora-all]
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.
AI_ONLY_REPORT
package: libkcapi-1.5.0-3.el10
Summary: IV Reuse in Symmetric Cipher Chunking: large one-shot symmetric
cipher operations can resend the original IV for each internal chunk,
restarting cipher state and breaking expected continuous-message behavior.
Requirements to exploit: An attacker must be able to make an application
using `libkcapi-1.5.0-3.el10` call the one-shot symmetric cipher APIs on
data larger than `sy
Bugzilla
CVE-2026-71225 libkcapi: IV reuse in libkcapi one-shot symmetric cipher chunking causes cipher state reset across chunk boundaries
bugzilla·2026-04-26·CVSS 6.5
CVE-2026-71225 [MEDIUM] CVE-2026-71225 libkcapi: IV reuse in libkcapi one-shot symmetric cipher chunking causes cipher state reset across chunk boundaries
CVE-2026-71225 libkcapi: IV reuse in libkcapi one-shot symmetric cipher chunking causes cipher state reset across chunk boundaries
AI_ONLY_REPORT
package: libkcapi-1.5.0-3.el10
Summary: IV Reuse in Symmetric Cipher Chunking: large one-shot symmetric
cipher operations can resend the original IV for each internal chunk,
restarting cipher state and breaking expected continuous-message behavior.
Requirements to exploit: An attacker must be able to make an application
using `libkcapi-1.5.0-3.el10` call the one-shot symmetric cipher APIs on
data larger than `sysconf(_SC_PAGESIZE) * ALG_MAX_PAGES` (typically 64 KiB)
in an affected stateful mode such as `ctr` or `cbc`, and observe the
resulting ciphertext or decryption behavior. Reachability depends on the
consuming application; the available evi
https://access.redhat.com/errata/RHSA-2026:56985https://access.redhat.com/errata/RHSA-2026:67265https://access.redhat.com/errata/RHSA-2026:67266https://access.redhat.com/errata/RHSA-2026:67267https://access.redhat.com/errata/RHSA-2026:69285https://access.redhat.com/errata/RHSA-2026:87712https://access.redhat.com/security/cve/CVE-2026-71225https://bugzilla.redhat.com/show_bug.cgi?id=2462011
2026-08-05
Published