Vulnerability · Published Mar 30, 2026 · Assigned by GitHub_M
CVE-2026-32884Botan: Case-Insensitive CN Values Bypass DNS excludedSubtrees Name Constraints (RFC 5280 Violation)
Medium 5.9
In plain English
A medium-severity improper certificate validation 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 0.2% (higher than 6% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.24 | botan3 | 3.11.0-r0 | ALPINE-CVE-2026-32884 |
| Debian:12 | botan | no fix listed | DEBIAN-CVE-2026-32884 |
| Debian:13 | botan | no fix listed | DEBIAN-CVE-2026-32884 |
| Debian:13 | botan3 | 3.11.0+dfsg-2 | DEBIAN-CVE-2026-32884 |
| Debian:14 | botan3 | 3.11.0+dfsg-2 | DEBIAN-CVE-2026-32884 |
| Ubuntu:25.10 | botan | no fix listed | UBUNTU-CVE-2026-32884 |
| Ubuntu:25.10 | botan3 | no fix listed | UBUNTU-CVE-2026-32884 |
| Ubuntu:26.04:LTS | botan3 | no fix listed | UBUNTU-CVE-2026-32884 |
| Ubuntu:26.10 | botan3 | no fix listed | UBUNTU-CVE-2026-32884 |
Affected products (as reported)
Weakness: CWE-295 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
References
- https://github.com/randombit/botan/security/advisories/GHSA-7c3g-7763-ggj5 x_refsource_CONFIRM