DEBIAN-CVE-2026-27586
Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, two swallowed errors in `ClientAuthentication.provision()` cause mTLS client certificate authentication to silently fail open when a CA certificate file is missing, unreadable, or malformed. The server starts without error but accepts any client certificate signed by any system-trusted CA, completely bypassing the intended private CA trust boundary. Any deployment using `trusted_ca_cert_file` or `trusted_ca_certs_pem_files` for mTLS will silently degrade to accepting any system-trusted client certificate if the CA file becomes unavailable. This can happen due to a typo in the path, file rotation, corruption, or permission changes. The server gives no indication that mTLS is misconfigured. Version 2.11.1 fixes the vulnerability.
DEBIAN-CVE-2026-27586
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:DEBIAN-CVE-2026-27586
caddy
Source reference: /affected/0/package/name
- Affected versions
- 2.11.2-1~bpo13+1
Source reference:
/affected/0/versions2.6.2-12Source reference:
/affected/0/versions2.6.2-13Source reference:
/affected/0/versions2.6.2-14Source reference:
/affected/0/versions - Fixed versions
- 2.11.2-1
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.11.2-1"
}
]
}
],
"package": {
"name": "caddy",
"purl": "pkg:deb/debian/caddy?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"2.11.2-1~bpo13+1",
"2.6.2-12",
"2.6.2-13",
"2.6.2-14"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27586.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #56303 · Revision 1
- Added to Heist Feed
- Publisher date