Read the docs
TI-2026-25343 Aliases CVE-2026-32884

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

Priority LOW 26CWE-295Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
Spoofing
Confidentiality · integrity · availability
None · High · None
Fix status
Partial Red Hat: 1 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-295.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00165 5th percentileScored 2026-11-07
Fix Partial botan (randombit): 3.11.0Red Hat: 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
randombitbotanbefore 3.11.03.11.0Patch availableCNA
  • botan Vendorrandombit Affected before 3.11.0 Fixed in 3.11.0 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:botan_project:botan:*:*:*:*:*:*:*:*before 3.11.0Vulnerablerandombit
  • cpe:2.3:a:botan_project:botan:*:*:*:*:*:*:*:* Versions before 3.11.0 Vulnerable ·randombit

Remediation

  • Fix · CNA botan (randombit) Fixed in 3.11.0

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-32884

References

Advisory 1

  • TI-2024-33818 Botan before 3.6.0, when certain GCC versions are used, has a compiler-induced… CVSS 3.1MEDIUM 5.9
  • TI-2024-33817 Botan before 3.6.0, when certain LLVM versions are used, has compiler-induced… CVSS 3.1MEDIUM 5.9
  • TI-2016-02004 Integer overflow in the PointGFp constructor in Botan before 1.10.11 and 1.11.x before… CVSS 3.0CRITICAL 9.8
  • TI-2016-02005 Heap-based buffer overflow in the P-521 reduction function in Botan 1.11.x before 1.11.27… CVSS 3.0CRITICAL 9.8
  • TI-2026-26828 Botan has a certificate authentication bypass due to trust anchor confusion CVSS 4.0CRITICAL 9.3
  • TI-2016-07479 In Botan 1.8.0 through 1.11.33, when decoding BER data an integer overflow could occur… CVSS 3.0CRITICAL 9.8
See all 34 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences