# CVE-2026-32884: Botan: Case-Insensitive CN Values Bypass DNS excludedSubtrees Name Constraints (RFC 5280 Violation)

> Attackers can bypass DNS name constraints in X.509 certificates using mixed-case Common Names, allowing unauthorized certificate validation.

- **Severity:** Medium 5.9 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N`)
- **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-2026-32884, AZL-81180, DEBIAN-CVE-2026-32884, GHSA-7c3g-7763-ggj5, UBUNTU-CVE-2026-32884, openSUSE-SU-2026:20566-1

## What is CVE-2026-32884?

CVE-2026-32884 is a medium-severity 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. Prior to version 3.11.0, during processing of an X.509 certificate path using name constraints which restrict the set of allowable DNS names, if no subject alternative name is defined in the end-entity certificate Botan would check that the CN was allowed by the DNS name constraints, even though this check is technically not required by RFC 5280. However this check failed to account for the possibility of a mixed-case CN. Thus a certificate with CN=Sub.EVIL.COM and no subject alternative name would bypasses an excludedSubtrees constraint for evil.com because the comparison is case-sensitive. This issue has been patched in version 3.11.0.

Weakness: CWE-295 (Improper Certificate Validation)

## Which versions are affected by CVE-2026-32884?

It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `Botan` | openSUSE:Leap 16.0 | All versions | 3.7.1-160000.4.1 |

Products: Botan Project Botan.

## How do I fix CVE-2026-32884?

Upgrade to a fixed version.

## Is CVE-2026-32884 being exploited?

There is no known exploitation of CVE-2026-32884 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-2026-32884 and fix it if it is affected.

What it is: CVE-2026-32884 is a medium-severity 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-2026-32884 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-2026-32884/ (Markdown: https://insights.sbomify.com/CVE-2026-32884/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-32884
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-32884
- OSV: https://osv.dev/vulnerability/CVE-2026-32884

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-32884/
Summaries are generated and may contain mistakes; the official description above is the record.