Plaintext relationship disclosure via per-chunk IV reuse
Published Aug 5, 2026 · Updated Aug 25, 2026
Cryptographic state reuse in libkcapi 0.10.1 through 1.5.0 allows remote attackers to expose plaintext relationships via large cipher inputs. One-shot CTR and CBC operations split inputs over 64 KiB into internal chunks but reapply the original IV instead of carrying cipher state across chunk boundaries. Exploitation requires an application to pass attacker-controlled large input to an affected one-shot API; the result weakens confidentiality and can produce incorrect ciphertext.
Summary
What happened
Cryptographic state reuse in libkcapi 0.10.1 through 1.5.0 allows remote attackers to expose plaintext relationships via large cipher inputs. One-shot CTR and CBC operations split inputs over 64 KiB into internal chunks but reapply the original IV instead of carrying cipher state across chunk boundaries. Exploitation requires an application to pass attacker-controlled large input to an affected one-shot API; the result weakens confidentiality and can produce incorrect ciphertext.
The record
- CVE
- CVE-2026-71225
- Published
- Aug 5, 2026
- Updated
- Aug 25, 2026
- Vendor
- Stephan Mueller
- Product
- libkcapi
- Classifications
- CWE-330
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 5, 2026CVE publishedPublication date reported by the CVE source.
- Aug 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0.10.1 <1.5.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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