Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:HSummary
CVE-2026-32877 is a high-severity Out-of-bounds Read (CWE-125) vulnerability in Botan Project Botan. Its CVSS base score is 8.2 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 20th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-32877 is a vulnerability in Botan, a C++ cryptography library, affecting versions from 2.3.0 up to but not including 3.11.0. The issue occurs during SM2 decryption, where the code responsible for verifying the authentication code value (C3) does not check if the encoded value matches the expected length before performing the comparison. This flaw enables an invalid ciphertext to trigger a heap over-read of up to 31 bytes, potentially leading to a crash or other undefined behavior. The vulnerability is classified under CWE-125 (Out-of-bounds Read) with a CVSS v3.1 base score of 8.2 (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H).
A remote, unauthenticated attacker can exploit this vulnerability over the network with low complexity and no user interaction required. By supplying a specially crafted invalid ciphertext to an application using the affected Botan versions for SM2 decryption, the attacker can induce a heap over-read. This results in high availability impact through application crashes, low confidentiality impact from potential information disclosure via the over-read, and no integrity impact, though undefined behavior could lead to further consequences depending on the context.
The Botan project has addressed this issue in version 3.11.0, where the decryption code now properly validates the length of the C3 value prior to comparison. Security practitioners should upgrade to Botan 3.11.0 or later. Additional details are available in the project's security advisory at https://github.com/randombit/botan/security/advisories/GHSA-7jj6-4r42-w9h6.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-17210
Vulnerability Data
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.…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
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Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation directly finds out-of-bounds read flaws through static analysis, fuzzing, and dynamic bounds checks.
Secure engineering principles require bounds checking and memory-safe constructs that stop out-of-bounds reads from being introduced.
Process isolation confines the effects of an out-of-bounds read to the compromised process.
Input validation rejects malformed indices or lengths that would otherwise cause reads outside buffer bounds.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure-development practices such as bounds checking and memory-safe languages directly prevent out-of-bounds reads.
Vulnerability scanning and recording can discover instances of out-of-bounds reads after code is deployed.
Routine patching replaces vulnerable code containing out-of-bounds read flaws.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development and acceptance includes fuzzing and static analysis that detect out-of-bounds read defects before release.
Logging can record evidence of an out-of-bounds read but does not prevent the weakness itself.
Secure development life cycle mandates input validation and bounds checking that directly prevent out-of-bounds reads.
Application security requirements include explicit bounds and memory-safety specifications that mitigate buffer over-reads.
Secure system architecture and engineering principles require memory-safe design patterns and runtime protections against out-of-bounds access.
Secure coding standards explicitly forbid unsafe pointer arithmetic and mandate bounds-checked reads, eliminating CWE-125.