Caddy before 0.10.13 mishandles TLS client authentication, as demonstrated by an…
Priority MEDIUM 47CWE-287Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and GitHub. Impact type from CWE-287.
Summary
Caddy before 0.10.13 mishandles TLS client authentication, as demonstrated by an authentication bypass caused by the lack of the StrictHostMatching mode.
Why it matters now
EPSS 0.02723 86th percentileScored 2026-11-07
Fix Fixed github.com/caddyserver/caddy (Go): 0.10.13
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 0.10.13 | 0.10.13 | Patch available | GHSA-gr7w-x2jp-3xgw |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
- github.com/caddyserver/caddy (Go) Vendor— Affected before 0.10.13 Fixed in 0.10.13 Patch available GHSA-gr7w-x2jp-3xgw
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:caddyserver:caddy:*:*:*:*:*:*:*:* | before 0.10.3 | Vulnerable | caddyserver |
- cpe:2.3:a:caddyserver:caddy:*:*:*:*:*:*:*:* Versions before 0.10.3 Vulnerable ·caddyserver
Remediation
- Fix · GHSA-gr7w-x2jp-3xgw github.com/caddyserver/caddy (Go) Fixed in 0.10.13 Advisory →
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2018-21246
- 2026-10-03 Alias added: GHSA-gr7w-x2jp-3xgw
References
Advisory 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-2018-21246 · CVE Program
- CVE-2018-21246 · NVD
- FIRST EPSS
- GHSA-gr7w-x2jp-3xgw · GitHub Advisory Database · CC BY 4.0
- CVE-2018-21246 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences