How severe is CVE-2020-11053?

CVE-2020-11053 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2020-11053 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-11053?

CVE-2020-11053 affects Oauth2 Proxy Project Oauth2 Proxy. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-11053?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2020-11053 published?

CVE-2020-11053 was published on 2020-05-07 and last updated on 2026-06-17.

CVE-2020-11053

CVE-2020-11053 is a high-severity vulnerability in Oauth2 Proxy Project Oauth2 Proxy with a CVSS 3.x base score of 7.1. 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-601.

Key facts

Severity: High (CVSS 3.x base score 7.1)
CVSS v2: 5.8
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-601
Affected product: Oauth2 Proxy Project Oauth2 Proxy
Published: 2020-05-07
Last modified: 2026-06-17

Description

In OAuth2 Proxy before 5.1.1, there is an open redirect vulnerability. Users can provide a redirect address for the proxy to send the authenticated user to at the end of the authentication flow. This is expected to be the original URL that the user was trying to access. This redirect URL is checked within the proxy and validated before redirecting the user to prevent malicious actors providing redirects to potentially harmful sites. However, by crafting a redirect URL with HTML encoded whitespace characters the validation could be bypassed and allow a redirect to any URL provided. This has been patched in 5.1.1.

Frequently asked questions

What is CVE-2020-11053?: In OAuth2 Proxy before 5.1.1, there is an open redirect vulnerability. Users can provide a redirect address for the proxy to send the authenticated user to at the end of the authentication flow. This is expected to be the original URL that the user was trying to access. This redirect URL is checked within the proxy and validated before redirecting the user to prevent malicious actors providing redirects to potentially harmful sites. However, by crafting a redirect URL with HTML encoded whitespace characters the validation could be bypassed and allow a redirect to any URL provided. This has been patched in 5.1.1.
How severe is CVE-2020-11053?: CVE-2020-11053 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2020-11053 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-11053?: CVE-2020-11053 affects Oauth2 Proxy Project Oauth2 Proxy. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-11053?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-11053 published?: CVE-2020-11053 was published on 2020-05-07 and last updated on 2026-06-17.

References

https://github.com/oauth2-proxy/oauth2-proxy/security/advisories/GHSA-j7px-6hwj-hpjg

Affected products (1)

cpe:2.3:a:oauth2_proxy_project:oauth2_proxy:*:*:*:*:*:*:*:*

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