CVE-2020-26244

Cryptographic issues in Python oic

MEDIUM
6.8
CVSS Score
Published: December 2, 2020 at 08:05 PM UTC
Updated: June 17, 2026 at 03:07 AM UTC
2 products affected across 2 vendorsPython Openid ConnectOpenid Connect Project Python Openid Connect

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Severity
MEDIUM6.8
Exploit prediction
EPSS 0.8%

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.2.1
Affected range stops below 1.2.1, so it looks safe — our inference, not a vendor statement
v < 1.2.1
Affected range stops below 1.2.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

CVSS

6.8MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
HIGH
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-325CWE-347

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