CVE-2026-32877 Botan: Heap Buffer Over-read in SM2 Decryption via Undersized C3 Hash Field
An attacker can cause a crash or undefined behavior in Botan via a heap over-read during SM2 decryption due to missing length checks.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-32877?
CVE-2026-32877 is a high-severity memory corruption vulnerability in randombit botan, published on 30 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-125
Which versions are affected by CVE-2026-32877?
It affects 1 product.
Products include Botan Project Botan.
How do I fix CVE-2026-32877?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-32877 being exploited?
There is no known exploitation of CVE-2026-32877 in the wild and no public exploit code.
Other vulnerabilities in randombit botan
Sources
Also known as ALPINE-CVE-2026-32877, DEBIAN-CVE-2026-32877, GHSA-7jj6-4r42-w9h6, UBUNTU-CVE-2026-32877.