CVE-2026-30852
7.5 · HIGHOverview
CVE-2026-30852 is a high-severity vulnerability affecting caddyserver caddy. It was published on March 7, 2026 and has a CVSS 3.1 base score of 7.5 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
Caddy is an extensible server platform that uses TLS by default. From version 2.7.5 to before version 2.11.2, the vars_regexp matcher in vars.go:337 double-expands user-controlled input through the Caddy replacer. When vars_regexp matches against a placeholder like {http.request.header.X-Input}, the header value gets resolved once (expected), then passed through repl.ReplaceAll() again (the bug). This means an attacker can put {env.DATABASE_URL} or {file./etc/passwd} in a request header and the server will evaluate it, leaking environment variables, file contents, and system info. This issue has been patched in version 2.11.2.
Remediation
Check the references section for vendor advisories and patches from caddyserver. Update caddy to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| caddyserver | caddy | >= 2.7.5, < 2.11.2 | Affected |
Frequently Asked Questions
What is CVE-2026-30852?
CVE-2026-30852 is a high-severity vulnerability affecting caddyserver caddy. It was published on March 7, 2026 and has a CVSS 3.1 base score of 7.5 (HIGH).
How severe is CVE-2026-30852?
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-30852?
Check the references section for vendor advisories and patches from caddyserver. Update caddy to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-30852?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-30852 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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