What is CVE-2020-5233?

CVE-2020-5233 is a medium-severity vulnerability in Oauth2 Proxy Project, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 5.9/10. Published 2020-01-30.

How severe is CVE-2020-5233?

Medium severity. CVSS v3 base score is 5.9 out of 10.

Open Redirect in Oauth2 Proxy Project

CVE-2020-5233

OAuth2 Proxy before 5.0 has an open redirect vulnerability. Authentication tokens could be silently harvested by an attacker. This has been patched in version 5.0.

Vulnerability class: Open Redirect

Published 2020-01-30 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:H/A:L.

EPSS exploit prediction

EPSS: 0.013 (70.3th percentile), scored 2026-10-24.

Low probability of exploitation in the next 30 days, but still tracked. 70th percentile — 70.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.013 · newest: 0.013 · change: 0.000

Affected products

Oauth2 Proxy Project
Pusher Oauth2 Proxy — versions < 5.0.0

Weakness classification (CWE)

CWE-601 — URL Redirection to Untrusted Site (Open Redirect)

References

github.com/pusher/oauth2_proxy/security/advisories/GHSA-qqxw-m5fj-f7gv (Exploit, Patch, Third Party Advisory)
github.com/pusher/oauth2_proxy/commit/a316f8a06f3c0ca2b5fc5fa18a91781b313607b2 (Patch, Third Party Advisory)
github.com/pusher/oauth2_proxy/releases/tag/v5.0.0 (Third Party Advisory, Release Notes)

Frequently asked questions

What is CVE-2020-5233?: CVE-2020-5233 is a medium-severity vulnerability in Oauth2 Proxy Project, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 5.9/10. Published 2020-01-30.
How severe is CVE-2020-5233?: Medium severity. CVSS v3 base score is 5.9 out of 10.