Caddy through 0.11.0 sends incorrect certificates for certain invalid requests, making it…
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Fixed
Attack profile from CVSS 3.0 · NVD. Fix status from CNA and GitHub. Impact type from CWE-200.
Summary
Caddy through 0.11.0 sends incorrect certificates for certain invalid requests, making it easier for attackers to enumerate hostnames. Specifically, when unable to match a Host header with a vhost in its configuration, it serves the X.509 certificate for a randomly selected vhost in its configuration. Repeated requests (with a nonexistent hostname in the Host header) permit full enumeration of all certificates on the server. This generally permits an attacker to easily and accurately discover the existence of and relationships among hostnames that weren't meant to be public, though this information could likely have been discovered via other methods with additional effort.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
| — | github.com/caddyserver/caddy (Go) | before 0.11.1 | 0.11.1 | Patch available | GHSA-jf2w-mq6r-56v8 |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
- github.com/caddyserver/caddy (Go) Vendor— Affected before 0.11.1 Fixed in 0.11.1 Patch available GHSA-jf2w-mq6r-56v8
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:caddyserver:caddy:*:*:*:*:*:*:*:* | up to 0.11.0 | Vulnerable | caddyserver |
- cpe:2.3:a:caddyserver:caddy:*:*:*:*:*:*:*:* Versions up to 0.11.0 Vulnerable ·caddyserver
Remediation
- Fix · GHSA-jf2w-mq6r-56v8 github.com/caddyserver/caddy (Go) Fixed in 0.11.1 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2018-19148
- 2026-10-03 Alias added: GHSA-jf2w-mq6r-56v8
References
Patch 3
More caddyserver Caddy vulnerabilities
- TI-2023-23979 The HTTP/2 protocol allows a denial of service (server resource consumption) because… KEVCVSS 3.1HIGH 7.5
- TI-2026-21978 Improper input validation in caddyserver caddy CVSS 4.0HIGH 8.9
- TI-2026-21974 Caddy's mTLS client authentication silently fails open when CA certificate file is missing or malformed CVSS 4.0HIGH 8.8
- TI-2026-23680 Improper authentication in caddyserver caddy CVSS 3.1HIGH 8.8
- TI-2026-21976 Caddy: MatchHost becomes case-sensitive for large host lists (>100), enabling host-based route/auth bypass CVSS 4.0HIGH 7.7
- TI-2026-21975 Caddy: MatchPath %xx (escaped-path) branch skips case normalization, enabling path-based route/auth bypass CVSS 4.0HIGH 7.7
Sources
- CVE-2018-19148 · CVE Program
- CVE-2018-19148 · NVD
- FIRST EPSS
- GHSA-jf2w-mq6r-56v8 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences