CVE-2026-48526
Description
A flaw was found in PyJWT, a Python library for JSON Web Token (JWT) implementation. When decoding JWTs, the library fails to validate the use of JSON Web Keys (JWK) in the HMAC algorithm while also supporting asymmetric algorithms. This allows a remote attacker to use the issuer's public key as the secret key for the HMAC algorithm, leading to the ability to forge JWTs. This vulnerability can result in authentication bypass or unauthorized access.
Statement
This Important vulnerability in PyJWT allows for authentication bypass and unauthorized access. It occurs when a JWT verifier is misconfigured to accept both symmetric and asymmetric algorithms, and a public JSON Web Key is erroneously used as the HMAC secret. Red Hat products are only affected if they utilize this specific, non-standard verifier configuration.
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 | N/A | 7.4 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | High | N/A | High |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | None | N/A | None |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/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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