Medium
libkcapi — security advisory
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.
- Products
- libkcapi
- Affected versions
- 0.13.0-0ubuntu1~ppa1, 0.13.0-0ubuntu1~ppa2, 1.0.0-2, 1.0.1-1, 1.0.2-1, 1.0.3-2, 1.0.3-2fips3, 1.1.3-1, 1.1.5-1, 1.1.5-1fips1, 1.2.1-1, 1.3.1-1, 1.3.1-2, 1.3.1-3, 1.4.0-1, 1.4.0-1ubuntu0.1~Fips1, 1.4.0-1ubuntu3, 1.4.0-1ubuntu4, 1.4.0-1ubuntu5
- Fixed versions
- Not specified
- CVEs
- CVE-2026-71225
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 03:14 UTC · Revision 1
Source evidence
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.
osv:UBUNTU-CVE-2026-71225
libkcapi
Fixed versions: Not specified
libkcapi
Fixed versions: Not specified
libkcapi
Fixed versions: Not specified
libkcapi
Fixed versions: Not specified
libkcapi
Fixed versions: Not specified
libkcapi
Fixed versions: Not specified
libkcapi
Fixed versions: Not specified
libkcapi
Fixed versions: Not specified
libkcapi
Fixed versions: Not specified
libkcapi
Fixed versions: Not specified
libkcapi
Fixed versions: Not specified
libkcapi
Fixed versions: Not specified
libkcapi
Fixed versions: Not specified
libkcapi
Fixed versions: Not specified
Complete source record
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],
"modified": "2026-10-17T13:00:44.809494035Z",
"provider": "osv",
"upstream": [
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],
"references": [
"https://ubuntu.com/security/CVE-2026-71225",
"https://www.cve.org/CVERecord?id=CVE-2026-71225",
"https://bugzilla.redhat.com/show_bug.cgi?id=2462011",
"https://access.redhat.com/security/cve/CVE-2026-71225"
]
},
"related_cves": [
{
"value": "CVE-2026-71225",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 360810,
"published_at": "2026-08-05T13:24:00+00:00"
}