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.
CVE-2026-30852
HIGHNVD 7.57.5
EchelonGraph scoreLOW confidence
This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: nvd
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.5Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.5
- EG Score
- 7.5(low)
- EG Risk
- 38(Track)EG Risk 38/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity75% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 33%
- KEV
- Not listed
Published
March 7, 2026
Last Modified
June 17, 2026
References (3)
- security-advisories@githubhttps://github.com/caddyserver/caddy/pull/5408
- security-advisories@githubhttps://github.com/caddyserver/caddy/releases/tag/v2.11.2
- security-advisories@githubhttps://github.com/caddyserver/caddy/security/advisories/GHSA-m2w3-8f23-hxxf
Weakness Classification(2)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 1× in last 7d / 1× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-27 13:37 UTCEG score recompute
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2026-30852?
CVE-2026-30852 is a high vulnerability published on March 7, 2026. Caddy is an extensible server platform that uses TLS by default. From version 2.7.5 to before version 2.11.2, the varsregexp matcher in vars.go:337 double-expands user-controlled input through the Caddy replacer. When varsregexp matches against a placeholder like {http.request.header.X-Input}, the…
When was CVE-2026-30852 disclosed?
CVE-2026-30852 was first published in the National Vulnerability Database on March 7, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-30852 actively exploited?
CVE-2026-30852 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 67.2% of all scored CVEs.
What is the CVSS score of CVE-2026-30852?
CVE-2026-30852 has a CVSS v3 base score of 7.5 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-30852?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-30852, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-30852
Is Your Infrastructure Affected by CVE-2026-30852?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.