# 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.

- **Severity:** High 8.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 30 Mar 2026
- **Updated:** 31 Mar 2026
- **Also known as:** ALPINE-CVE-2026-32877, DEBIAN-CVE-2026-32877, GHSA-7jj6-4r42-w9h6, UBUNTU-CVE-2026-32877

## 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 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-32877?

It affects 1 product.


Products: Botan Project Botan.

## How do I fix CVE-2026-32877?

Upgrade to a fixed version.

## 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

- [CVE-2021-24115](https://insights.sbomify.com/CVE-2021-24115/): Information disclosure in n/a (critical 9.8)
- [CVE-2018-9127](https://insights.sbomify.com/CVE-2018-9127/): Security feature bypass in n/a (critical 9.8)
- [CVE-2015-7826](https://insights.sbomify.com/CVE-2015-7826/): Security feature bypass in n/a (critical 9.8)
- [CVE-2016-6878](https://insights.sbomify.com/CVE-2016-6878/): Other in n/a (critical 9.8)
- [CVE-2016-9132](https://insights.sbomify.com/CVE-2016-9132/): Integer overflow in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-32877 and fix it if it is affected.

What it is: 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.
Exploitation: There is no known exploitation of CVE-2026-32877 in the wild and no public exploit code.

Affected product: randombit botan. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-32877/ (Markdown: https://insights.sbomify.com/CVE-2026-32877/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-32877
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-32877
- OSV: https://osv.dev/vulnerability/CVE-2026-32877

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-32877/
Summaries are generated and may contain mistakes; the official description above is the record.