CVE-2026-34610

Summary

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.

Affected Software

VendorProductVersion RangeStatus
smuellerDDleancrypto< 1.7.1affected

Weaknesses

  • CWE-681: CWE-681: Incorrect Conversion between Numeric Types

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References