Skip to content
Patch Next
Sign inAdd to your agent

← Actionable
Medium, CVSS 5.5

Caddy CVE-2026-30852 Fix Bypass

GHSA-wwhq-w58m-w29c

What to do

Vendor response not established. Follow the primary source's mitigation guidance and check back for a fix.

This page has no inventory attached, so it cannot say whether you are affected. A vendor fix is not proof that your deployment is fixed.

Add to your agent

Affected packages

  • Go github.com/caddyserver/caddy/v2

    Affected
    >= 2.11.0, <= 2.11.2
    Fixed in
    no fixed version recorded

Sources

Severity and exploitation
Exploitation
No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.
CVSS 4.0
5.5 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P · score source
EPSS
No dated EPSS signal available.
Source description

As published by the source; long descriptions are shortened.

TL;DR CVE-2026-30852 fixed double expansion in varsregexp when the variable key is a placeholder (e.g. {http.vars.x}). The fix does NOT protect literal key names (e.g. tenantid). An attacker injects {env.AWSSECRETACCESSKEY} or {file./etc/passwd} via a request header → Caddy expands it on the second pass → secrets leaked in response headers. Affected: Caddy v2.11.0 through v2.11.2 (latest). All versions since the CVE-2026-30852 fix. Root Cause modules/caddyhttp/vars.go, lines 215-217: Same issue at line 358-360 in MatchVarsRE. fromPlaceholder is false when the variable key is a literal string (not wrapped in {}). The fix only protects fromPlaceholder=true. Expansion chain: 1. Config: vars tenantid {http.request.header.X-Tenant-ID} 2. Request header: X-Tenant-ID: {env.SECRET} 3. Pass 1 (VarsMiddleware.ServeHTTP, line 63): repl.ReplaceAll("{http.request.header.X-Tenant-ID}", "") → resolves to literal string {env.SECRET}. Stored in vars map. 4. Pass 2 (VarsMatcher.MatchWithError, line…

Dates and revisions
Published by the source
Last modified by the source
Source last checked
  1. Revision 1 · created ·

    Published from ghsa record GHSA-wwhq-w58m-w29c

Agent brief

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: GHSA-wwhq-w58m-w29c

Advisory: Caddy CVE-2026-30852 Fix Bypass
IDs: GHSA-wwhq-w58m-w29c
Record: https://patchnext.com/advisories/ghsa-wwhq-w58m-w29c (revision 1, source checked 26 Oct 2026, 15:22 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/caddyserver/caddy/v2: affected >= 2.11.0, <= 2.11.2

## Suggested inspection (read-only)
- Go github.com/caddyserver/caddy/v2: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/caddyserver/caddy/v2.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-wwhq-w58m-w29c (GitHub-reviewed advisory GHSA-wwhq-w58m-w29c lists affected ranges: Go github.com/caddyserver/caddy/v2 >=2.11.0 <=2.11.2)

Commands are suggestions: review each one before running it.

Loading voting…