CVE-2026-32884
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedBotan 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceIn Botan versions prior to 3.11.0, X.509 certificate path validation incorrectly performs a case-sensitive comparison of the Common Name (CN) against DNS name constraints when no Subject Alternative Name (SAN) is present. This allows a certificate with CN=Sub.EVIL.COM to bypass an excludedSubtrees constraint for evil.com because the comparison treats uppercase and lowercase differently, despite DNS names being case-insensitive per RFC.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 3.11.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- High
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify the installed Botan library versionCheck the library file version or examine the botan version header (e.g., botan/version.h) if accessible. Many applications can also report the library version at runtime through a version API call.Affected if The detected version is any release prior to 3.11.0
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Determine if X.509 certificate validation with name constraints is in useReview application code or configuration to identify if X.509 certificate path validation is performed, particularly with excludedSubtrees or permittedSubtrees constraints applied to DNS names.Affected if The application performs X.509 validation using excludedSubtrees or permittedSubtrees constraints on DNS names
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Check if certificates rely on Common Name (CN) without SANExamine the certificates being validated. If the certificates lack Subject Alternative Name (SAN) extensions and validation relies on the CN field, this indicates the vulnerable code path could be triggered.Affected if Certificates being validated lack SAN entries and depend on CN for name matching
You are affected if your Botan library version is below 3.11.0 AND your X.509 validation uses DNS name constraints (excludedSubtrees/permittedSubtrees) on certificates that lack SAN entries and rely on CN matching.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped3.11.0
Upgrade Botan to version 3.11.0 or later. For applications using affected versions, recompile and redeploy with the patched library.
3.11.0
- Identify the current version of Botan library in use by checking project dependencies or build configuration
- Download Botan version 3.11.0 or later from the official source (github.com/botan/botan)
- Update the Botan library dependency in your project's dependency management system (e.g., package.json, requirements.txt, conanfile, etc.)
- Rebuild and recompile any applications or libraries that link against Botan
- Redeploy the updated application
- Verify that certificate validation now performs case-insensitive DNS name comparisons as per RFC 5280 standards
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-32884 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-32884 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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