CVE-2026-49272
Description
A flaw was found in OAuthLib. This vulnerability allows a remote attacker to bypass authentication and obtain unauthorized access tokens during the device authorization workflow. By submitting a token request with a valid client identifier alongside an invalid or missing device authorization code, the attacker can receive a valid bearer token without completing user approval, leading to unauthorized access to protected resources.
Statement
This vulnerability is rated as Important because a remote attacker with knowledge of a registered client identifier can bypass authentication mechanisms to acquire valid bearer tokens. Exploitation requires the authorization server to support and actively expose the RFC 8628 device authorization grant workflow. Deployments where the device authorization flow is not implemented or enabled are not susceptible to this flaw.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
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 | 8.5 | N/A | 8.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Changed | N/A | Changed |
| Confidentiality | Low | N/A | Low |
| Integrity Impact | High | N/A | High |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:N
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:N
Understanding the Weakness (CWE)
Access Control
Technical Impact: Bypass Protection Mechanism
An incorrect implementation may allow authentication to be bypassed.
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