Log in Start free

Vulnerability · Published Mar 30, 2026 · Assigned by GitHub_M

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

High 8.2

In plain English

A high-severity out-of-bounds read in botan from randombit. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 22% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.2High
Exploit odds (30 days)0.3%top 78.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Alpine:v3.24botan33.11.0-r0ALPINE-CVE-2026-32877
Debian:12botanno fix listedDEBIAN-CVE-2026-32877
Debian:13botanno fix listedDEBIAN-CVE-2026-32877
Debian:13botan33.11.0+dfsg-2DEBIAN-CVE-2026-32877
Debian:14botan33.11.0+dfsg-2DEBIAN-CVE-2026-32877
Ubuntu:25.10botanno fix listedUBUNTU-CVE-2026-32877
Ubuntu:25.10botan3no fix listedUBUNTU-CVE-2026-32877
Ubuntu:26.04:LTSbotan3no fix listedUBUNTU-CVE-2026-32877
Ubuntu:26.10botan3no fix listedUBUNTU-CVE-2026-32877

Affected products (as reported)

VendorProductVersions
randombit botan >= 2.3.0, < 3.11.0

Weakness: CWE-125 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H

References