What’s Vulnerable › Vulnerabilities

CVE-2020-26244: Cryptographic issues in Python oic

• Severity: medium (CVSS 6.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.8% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-12-02 · updated 2026-06-17
• Weakness: CWE-325

Description

Python oic is a Python OpenID Connect implementation. In Python oic before version 1.2.1, there are several related cryptographic issues affecting client implementations that use the library. The issues are: 1) The IdToken signature algorithm was not checked automatically, but only if the expected algorithm was passed in as a kwarg. 2) JWA `none` algorithm was allowed in all flows. 3) oic.consumer.Consumer.parse_authz returns an unverified IdToken. The verification of the token was left to the discretion of the implementator. 4) iat claim was not checked for sanity (i.e. it could be in the future). These issues are patched in version 1.2.1.

Affected products

• Python Openid Connect Project Python Openid Connect: before 1.2.1 — fixed in 1.2.1

How to fix

Upgrade to a fixed version: Python Openid Connect Project Python Openid Connect 1.2.1. Check the vendor advisory for mitigations.

References

• https://github.com/OpenIDC/pyoidc/commit/62f8d753fa17c8b1f29f8be639cf0b33afb02498
• https://github.com/OpenIDC/pyoidc/releases/tag/1.2.1
• https://github.com/OpenIDC/pyoidc/security/advisories/GHSA-4fjv-pmhg-3rfg
• https://pypi.org/project/oic/
• https://github.com/OpenIDC/pyoidc/commit/62f8d753fa17c8b1f29f8be639cf0b33afb02498
• https://github.com/OpenIDC/pyoidc/releases/tag/1.2.1
• https://github.com/OpenIDC/pyoidc/security/advisories/GHSA-4fjv-pmhg-3rfg
• https://pypi.org/project/oic/

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