CVE-2026-41479
Description
A flaw was found in Authlib, a Python library for building OAuth and OpenID Connect servers. A remote attacker can exploit the OAuth 2.0 authorization endpoint by providing an unsupported response type and a malicious redirect Uniform Resource Identifier (URI). This allows the attacker to redirect users to arbitrary external websites, potentially leading to information disclosure or phishing attacks. The vulnerability does not require authentication or a valid client registration.
Statement
Red Hat has assessed the impact of this vulnerability on Red Hat products. Products shipping Authlib 1.6.10 or later (1.6.x series) or 1.7.1 or later (1.7.x series) are not affected as they include the fix. Products shipping versions prior to 1.6.10 are affected at Moderate impact.
Mitigation
Upgrade Authlib to version 1.6.10 or later (for the 1.6.x series) or version 1.7.1 or later (for the 1.7.x series).
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.4 | N/A | 5.4 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | Required |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | Low | N/A | Low |
| Integrity Impact | Low | N/A | Low |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
Understanding the Weakness (CWE)
Access Control
Technical Impact: Bypass Protection Mechanism; Gain Privileges or Assume Identity
The user may be redirected to an untrusted page that contains malware which may then compromise the user's system. In some cases, an open redirect can also enable the immediate download of a file without the user's permission, because the redirection to an external site may lead to endpoints on those sites that automatically trigger a download action ("drive-by download" [REF-1478]). This will expose the user to extensive risk. The user's interaction with the web server may also be compromised if the malware conducts keylogging or other attacks that steal credentials, personally identifiable information (PII), or other important data.
Access Control,Confidentiality,Other
Technical Impact: Bypass Protection Mechanism; Gain Privileges or Assume Identity; Other
By modifying the URL value to a malicious site, an attacker may successfully launch a phishing scam. The user may be subjected to phishing attacks by being redirected to an untrusted page. The phishing attack may point to an attacker controlled web page that appears to be a trusted web site. The phishers may then steal the user's credentials and then use these credentials to access the legitimate web site. Because the server name in the modified link is identical to the original site, phishing attempts have a more trustworthy appearance.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
