What is CVE-2026-40575?

CVE-2026-40575 is a critical-severity vulnerability in Oauth2-proxy, classified under Authentication Bypass by Spoofing. CVSS score: 9.1/10. Published 2026-04-21.

How severe is CVE-2026-40575?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Vulnerability in Oauth2-proxy

CVE-2026-40575

OAuth2 Proxy is a reverse proxy that provides authentication using OAuth2 providers. Versions 7.5.0 through 7.15.1 may trust a client-supplied `X-Forwarded-Uri` header when `--reverse-proxy` is enabled and `--skip-auth-regex` or `--skip-au…

EPSS: 0.001 (26.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

Affected products

Oauth2-proxy — versions >= 7.5.0, < 7.15.2

Weakness classification (CWE)

CWE-290 — Authentication Bypass by Spoofing

References

https://github.com/oauth2-proxy/oauth2-proxy/security/advisories/GHSA-7x63-xv5r-3p2x (x_refsource_CONFIRM)

Frequently asked questions

What is CVE-2026-40575?: CVE-2026-40575 is a critical-severity vulnerability in Oauth2-proxy, classified under Authentication Bypass by Spoofing. CVSS score: 9.1/10. Published 2026-04-21.
How severe is CVE-2026-40575?: Critical severity. CVSS v3 base score is 9.1 out of 10.