CVE-2018-9127
Botan 2.2.0 - 2.4.0 (fixed in 2.5.0) improperly handled wildcard certificates and could accept certain certificates as valid for hostnames when, under RFC 6125 rules, they should not match.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.93%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Botan 2.2.0 - 2.4.0 (fixed in 2.5.0) improperly handled wildcard certificates and could accept certain certificates as valid for hostnames when, under RFC 6125 rules, they should not match. This only affects certificates issued to the same domain as the host, so to impersonate a host one must already have a wildcard certificate matching other hosts in the same domain. For example, b*.example.com would match some hostnames that do not begin with a 'b' character.
- CVSS 3.0
- 9.8 CRITICALCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.93% probability · 60th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-295
- Affected
- botan project/botan
- Source
- cve@mitre.org
EPSS 0.9% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://botan.randombit.net/security.htmlThird Party Advisory
- https://botan.randombit.net/security.htmlThird Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.