CVE-2026-30852

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.4%, top 67% of all CVEs by exploit prediction. 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: epss, 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.

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.

CVSS v3
7.5
EG Score
7.5(medium)
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 computed
Severity75% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
34%
KEV
Not listed

Published

March 7, 2026

Last Modified

June 17, 2026

Advisory Details (3)

Auto-updated Aug 2, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_pr, github_release.
github Patch Available🟡 PoC Available

vars_regexp double-expands user input, leaking env vars and files · Advisory · caddyserver/caddy · GitHub

https://github.com/caddyserver/caddy/security/advisories/GHSA-m2w3-8f23-hxxf
github_release Patch Available

v2.11.2

Patch available: caddyserver/caddy v2.11.2

https://github.com/caddyserver/caddy/releases/tag/v2.11.2
github_pr

caddyhttp: Fix `vars_regexp` matcher with placeholders

Fix merged in caddyserver/caddy PR #5408 on 2023-03-02 — awaiting tagged release

https://github.com/caddyserver/caddy/pull/5408

Affected Packages

(2 across 1 ecosystem)
Go(2)
PackageVulnerable rangeFixed inDependents
github.com/caddyserver/caddy/v2—2.11.2—
github.com/caddyserver/caddy/v2/modules/caddyhttp—2.11.2—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 7× in last 7d / 30× 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.

  1. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 19:27 UTCEPSS rescore
  3. 2026-09-17 19:30 UTCEPSS rescore
  4. 2026-09-16 14:08 UTCEPSS rescore
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  6. 2026-09-13 16:47 UTCEPSS rescore
  7. 2026-09-12 15:01 UTCEPSS rescore
  8. 2026-09-11 14:52 UTCEPSS rescore
  9. 2026-09-10 09:34 UTCEPSS rescore
  10. 2026-09-08 22:00 UTCEPSS rescore
  11. 2026-09-07 16:01 UTCEPSS rescore
  12. 2026-09-06 13:47 UTCEPSS rescore
  13. 2026-09-06 13:47 UTCEPSS rescore
  14. 2026-09-04 05:06 UTCEPSS rescore
  15. 2026-09-02 23:29 UTCOSV refresh
  16. 2026-09-02 14:11 UTCEPSS rescore
  17. 2026-09-01 13:53 UTCEPSS rescore
  18. 2026-09-01 04:39 UTCEPSS rescore
  19. 2026-09-01 04:39 UTCEPSS rescore
  20. 2026-08-30 19:17 UTCEPSS rescore
  21. 2026-08-30 01:22 UTCEPSS rescore
  22. 2026-08-28 21:41 UTCEPSS rescore
  23. 2026-08-27 14:25 UTCEPSS rescore
  24. 2026-08-26 14:46 UTCEPSS rescore
  25. 2026-08-25 13:49 UTCEPSS rescore
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  1. 2026-08-24 14:17 UTCEPSS rescore
  2. 2026-08-23 00:19 UTCEPSS rescore
  3. 2026-08-21 23:49 UTCEPSS rescore
  4. 2026-08-20 22:55 UTCEPSS rescore
  5. 2026-08-20 22:55 UTCEPSS rescore
  6. 2026-08-19 17:03 UTCEPSS rescore
  7. 2026-08-18 13:48 UTCEPSS rescore
  8. 2026-08-17 13:47 UTCEPSS rescore
  9. 2026-08-16 14:56 UTCEPSS rescore
  10. 2026-08-16 12:17 UTCEG score recompute
  11. 2026-08-16 02:14 UTCEPSS rescore
  12. 2026-08-15 01:30 UTCEPSS rescore
  13. 2026-08-14 08:12 UTCEG score recompute
  14. 2026-08-13 22:00 UTCEPSS rescore
  15. 2026-08-12 23:40 UTCEG score recompute
  16. 2026-08-12 13:50 UTCEPSS rescore
  17. 2026-08-11 22:29 UTCEG score recompute
  18. 2026-08-11 05:19 UTCEG score recompute
  19. 2026-08-11 00:00 UTCEPSS rescore
  20. 2026-08-09 20:55 UTCEG score recompute
  21. 2026-08-09 13:46 UTCEPSS rescore
  22. 2026-08-09 07:51 UTCEG score recompute
  23. 2026-08-08 16:37 UTCEPSS rescore
  24. 2026-08-07 19:17 UTCEG score recompute
  25. 2026-08-06 20:22 UTCEG score recompute
  26. 2026-08-06 13:46 UTCEPSS rescore
  27. 2026-08-06 02:20 UTCEG score recompute
  28. 2026-08-05 19:17 UTCEPSS rescore
  29. 2026-08-04 15:10 UTCEPSS rescore
  30. 2026-08-04 01:45 UTCEG score recompute
  31. 2026-08-03 10:36 UTCEPSS rescore
  32. 2026-08-02 18:32 UTCEG score recompute
  33. 2026-08-02 02:26 UTCEPSS rescore
  34. 2026-08-01 04:16 UTCEPSS rescore
  35. 2026-07-30 16:27 UTCEPSS rescore
  36. 2026-07-30 01:30 UTCEPSS rescore
  37. 2026-07-28 15:36 UTCEPSS rescore
  38. 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 65.9% 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).
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

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