Review reviewCritical

CVE-2026-40575

oauth2-proxy oauth2-proxy, Red Hat Ceph Storage 9, oauth2 proxy

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-auth-route` is configured. An attacker can spoof this header so OAuth2 Proxy evaluates authentication and skip-auth rules against a different path than the one actually sent to the upstream application. This can result in an unauthenticated remote attacker bypassing authentication and accessing protected routes without a valid session. Impacted users are dep...

CVSS: 9.1
EPSS: 0.48%
CISA KEV: Not listed
Published: 2026.04.22

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.48%

Technical severityCVSS 9.1

Vulnerability overview

Affected product and versions

Product: oauth2-proxy oauth2-proxy, Red Hat Ceph Storage 9, oauth2 proxy
Affected versions: >= >= 7.5.0, < 7.15.2, >= 7.5.0 < 7.15.2
Fixed versions: 7.15.2

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that oauth2-proxy oauth2-proxy, Red Hat Ceph Storage 9, oauth2 proxy and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CWE: CWE-290