CVE-2026-32877 HIGH

CVE-2026-32877: Botan: Heap Buffer Over-read in SM2 Decryption via Undersized C3 Hash Field

Vendor Randombit
Product botan
Weakness CWE-125
Published March 30, 2026
Last update March 31, 2026

CVSS base score

8.2/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality Low
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H

What the vulnerability does

01Description

Botan is a C++ cryptography library. From version 2.3.0 to before version 3.11.0, during SM2 decryption, the code that checked the authentication code value (C3) failed to check that the encoded value was of the expected length prior to comparison. An invalid ciphertext can cause a heap over-read of up to 31 bytes, resulting in a crash or potentially other undefined behavior. This issue has been patched in version 3.11.0.

Key dates

02Disclosure timeline

March 30, 2026 CVE published
March 31, 2026 Record updated