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CVE-2026-34610 Detail

Description

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.


Metrics

NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://github.com/smuellerDD/leancrypto/commit/5cdcbe12bd6c3d6e87e969972a580b44a74c3a6a GitHub, Inc.
https://github.com/smuellerDD/leancrypto/releases/tag/v1.7.1 GitHub, Inc.
https://github.com/smuellerDD/leancrypto/security/advisories/GHSA-636g-jxv4-v4gr GitHub, Inc.

Weakness Enumeration

CWE-ID CWE Name Source
CWE-681 Incorrect Conversion between Numeric Types GitHub, Inc.  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-34610
NVD Published Date:
04/02/2026
NVD Last Modified:
04/02/2026
Source:
GitHub, Inc.