High severity · published Mar 30, 2026
CVE-2026-32877
Botan: Heap Buffer Over-read in SM2 Decryption via Undersized C3 Hash Field
8.2
CVSS
0.3%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 21% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
BO
botan · randombit
>= 2.3.0, < 3.11.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-32877
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-32877
Vendor Advisory
https://github.com/randombit/botan/security/advisories/GHSA-7jj6-4r42-w9h6
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