Vulnerability Details CVE-2026-34610
The leancrypto library is a cryptographic library that exclusively contains only PQC-resistant cryptographic algorithms. Prior to version 1.7.1, lc_x509_extract_name_segment() casts size_t vlen to uint8_t when storing the Common Name (CN) length. An attacker who crafts a certificate with CN = victim's CN + 256 bytes padding gets cn_size = (uint8_t)(256 + N) = N, where N is the victim's CN length. The first N bytes of the attacker's CN are the victim's identity. After parsing, the attacker's certificate has an identical CN to the victim's — enabling identity impersonation in PKCS#7 verification, certificate chain matching, and code signing. This issue has been patched in version 1.7.1.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.0
EPSS Ranking 5.7%
CVSS Severity
CVSS v3 Score 5.9
References
Products affected by CVE-2026-34610
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cpe:2.3:a:leancrypto:leancrypto:0.10.0
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cpe:2.3:a:leancrypto:leancrypto:0.10.1
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cpe:2.3:a:leancrypto:leancrypto:0.11.0
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cpe:2.3:a:leancrypto:leancrypto:0.3.0
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cpe:2.3:a:leancrypto:leancrypto:0.4.0
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cpe:2.3:a:leancrypto:leancrypto:0.5.0
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cpe:2.3:a:leancrypto:leancrypto:0.5.1
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cpe:2.3:a:leancrypto:leancrypto:0.5.2
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cpe:2.3:a:leancrypto:leancrypto:0.5.3
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cpe:2.3:a:leancrypto:leancrypto:0.6.0
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cpe:2.3:a:leancrypto:leancrypto:0.7.0
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cpe:2.3:a:leancrypto:leancrypto:0.8.0
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cpe:2.3:a:leancrypto:leancrypto:0.9.0
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cpe:2.3:a:leancrypto:leancrypto:0.9.1
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cpe:2.3:a:leancrypto:leancrypto:0.9.2
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cpe:2.3:a:leancrypto:leancrypto:1.0.0
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cpe:2.3:a:leancrypto:leancrypto:1.0.1
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cpe:2.3:a:leancrypto:leancrypto:1.1.0
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cpe:2.3:a:leancrypto:leancrypto:1.2.0
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cpe:2.3:a:leancrypto:leancrypto:1.3.0
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cpe:2.3:a:leancrypto:leancrypto:1.4.0
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cpe:2.3:a:leancrypto:leancrypto:1.5.0
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cpe:2.3:a:leancrypto:leancrypto:1.5.1
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cpe:2.3:a:leancrypto:leancrypto:1.6.0
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cpe:2.3:a:leancrypto:leancrypto:1.7.0