How severe is CVE-2020-26244?

CVE-2020-26244 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2020-26244 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-26244?

CVE-2020-26244 affects Python Openid Connect Project Python Openid Connect. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-26244?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2020-26244 published?

CVE-2020-26244 was published on 2020-12-02 and last updated on 2026-06-17.

CVE-2020-26244

CVE-2020-26244 is a medium-severity vulnerability in Python Openid Connect Project Python Openid Connect with a CVSS 3.x base score of 6.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-347.

Key facts

Severity: Medium (CVSS 3.x base score 6.8)
CVSS v2: 4.9
EPSS exploit prediction: 1% (53rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-347
Affected product: Python Openid Connect Project Python Openid Connect
Published: 2020-12-02
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2020-26244?: 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.
How severe is CVE-2020-26244?: CVE-2020-26244 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over network with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2020-26244 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-26244?: CVE-2020-26244 affects Python Openid Connect Project Python Openid Connect. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-26244?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2020-26244 published?: CVE-2020-26244 was published on 2020-12-02 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:python_openid_connect_project:python_openid_connect:*:*:*:*:*:*:*:*

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