5.9

CVE-2026-32884: botan_project botan Improper Certificate Validation

CVSS: 5.9v3.1MediumAnalyzed
AliasesALPINE-CVE-2026-32884UBUNTU-CVE-2026-32884DEBIAN-CVE-2026-32884
Published 30-03-2026Last modified 31-03-2026
Open JSON

Vulnerability summary

CVE-2026-32884 is a medium (CVSS 5.9) Improper Certificate Validation vulnerability in botan_project botan. EPSS estimates a 0.20% chance of exploitation in the next 30 days, higher than 8.8% of scored vulnerabilities.

Overall risk
24/100
0100
Low · default modelHow is this calculated?
CVSS score
5.9/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.20%
0%100%
Low · +0.04 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 30-03-2026
    PublishedVulnerability first disclosed.
  2. 31-03-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

5 scores · 5 sources · 1 version

EPSS trend

Probability

0.20%

Chance of exploitation in the next 30 days

Percentile

9%

Versus all other CVEs

30-day change

+0.04 pp

From 0.16% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.20%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Ubuntu3 products
  • botanAll versions (No fix recorded)
  • botan1.10All versions (No fix recorded)
  • botan3All versions (No fix recorded)
Debian2 products
  • botanAll versions (No fix recorded)
  • botan3< 3.11.0+dfsg-2
Alpine1 product
  • botan3< 3.11.0-r0
Botan_project1 product
Opensuse1 product
  • Botan&distro=openSUSE Leap 16.0< 3.7.1-160000.4.1
Randombit1 product

6 vendors · 9 products

References

7 links