CVE-2026-114616
Description
A flaw was found in Authlib. The library improperly accepts zero-length key material during Hash-based Message Authentication Code (HMAC) signing and verification. If a host application verifies tokens using a secret that evaluates to an empty value, a remote attacker can generate predictable signatures for arbitrary token claims. This allows the attacker to forge authentic-looking tokens and bypass authentication controls.
Statement
This vulnerability is rated as Important severity because successful exploitation enables remote unauthenticated token forgery and full authentication bypass, though the risk is constrained by the prerequisite that the consuming service must resolve HMAC secrets to empty values. In standard Red Hat deployments, underlying services and containerized offerings enforce or dynamically provision defined secret keys, substantially reducing exposure under default configurations. However, if an application environment fails to supply a secret or allows key lookups to return blank values, external actors can generate predictable signatures and gain unauthorized access.
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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.4 | 9.1 | 7.4 |
| Attack Vector | Network | Network | Network |
| Attack Complexity | High | Low | High |
| Privileges Required | None | None | None |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | High | High | High |
| Integrity Impact | High | High | High |
| Availability Impact | None | None | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
Understanding the Weakness (CWE)
Access Control,Integrity,Confidentiality
Technical Impact: Gain Privileges or Assume Identity; Modify Application Data; Execute Unauthorized Code or Commands
An attacker could gain access to sensitive data and possibly execute unauthorized code.
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