Vulnerability · Published Oct 22, 2026 · Assigned by GitHub_M

CVE-2026-114614Authlib: is_secure_transport() loopback exemption can be bypassed with a userinfo component, allowing cleartext-HTTP URLs to non-loopback hosts

Low 2.6

In plain English

A low-severity open redirect in authlib from authlib. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)2.6Low

Exploit odds (30 days)0.3%top 80.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	python-authlib	no fix listed	DEBIAN-CVE-2026-114614
Debian:13	python-authlib	no fix listed	DEBIAN-CVE-2026-114614
Debian:14	python-authlib	1.9.1-1	DEBIAN-CVE-2026-114614
PyPI	authlib	1.8.0	GHSA-jj7h-c3hg-m23x
PyPI	authlib	1.8.0	PYSEC-2026-4354
Ubuntu:26.10	python-authlib	no fix listed	UBUNTU-CVE-2026-114614

Affected products (as reported)

Vendor	Product	Versions
authlib	authlib	< 1.8.0

Weakness: CWE-601, CWE-693 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:N/A:N

References

https://github.com/authlib/authlib/security/advisories/GHSA-jj7h-c3hg-m23x x_refsource_CONFIRM
https://github.com/authlib/authlib/commit/95ad1f90acf0c7b9cf2a8f25e6eb3f1135b8dc70 x_refsource_MISC
https://github.com/authlib/authlib/releases/tag/v1.8.0 x_refsource_MISC