Authlib: is_secure_transport() loopback exemption can be bypassed with a userinfo component, allowing cleartext-HTTP URLs to non-loopback hosts
Authlib is a Python library which builds OAuth and OpenID Connect servers. From 0.13 until 1.8.0, authlib.common.security.is_secure_transport() uses a textual prefix comparison for loopback HTTP exemptions, so a URL whose userinfo begins with a loopback host can be accepted even when its parsed host is an external non-loopback system. An external party able to supply a URL to OIDC RP-Initiated Logout registration, authorization-server metadata validation, or another call site can bypass the TLS-required guard and cause cleartext redirection or acceptance of cleartext endpoints. The issue does not bypass redirect URI exact matching and does not by itself forge tokens or authenticate users. The vulnerable authlib.common.security.is_secure_transport() implementation in authlib/common/security.py misinterprets the userinfo component before OIDC RP-Initiated Logout dynamic client registration and other consumers enforce transport security. This issue is fixed in version 1.8.0.
CVE-2026-114614
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: cve:CVE-2026-114614
authlib
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "authlib",
"product": "authlib",
"versions": [
{
"status": "affected",
"version": "< 1.8.0"
}
]
}
]- Related CVEs
- CVE-2026-114614
Source reference:
/cveMetadata/cveId
Publisher severity
low
Source reference: /containers/cna/metrics
- Event
- #52419 · Revision 1
- Added to Heist Feed
- Publisher date