Upstream information

CVE-2026-40575 at MITRE

Description

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 deployments that run oauth2-proxy with `--reverse-proxy` enabled and configure at least one `--skip-auth-regex` or `--skip-auth-route` rule. This issue is patched in `v7.15.2`. Some workarounds are available for those who cannot upgrade immediately. Strip any client-provided `X-Forwarded-Uri` header at the reverse proxy or load balancer level; explicitly overwrite `X-Forwarded-Uri` with the actual request URI before forwarding requests to OAuth2 Proxy; restrict direct client access to OAuth2 Proxy so it can only be reached through a trusted reverse proxy; and/or remove or narrow `--skip-auth-regex` / `--skip-auth-route` rules where possible. For nginx-based deployments, ensure `X-Forwarded-Uri` is set by nginx and not passed through from the client.

Other Security Trackers

SUSE information

Overall state of this security issue: Resolved

This issue is currently rated as having critical severity.

CVSS v3 Scores
CVSS detail CNA (0b0ca135-0b70-47e7-9f44-1890c2a1c46c) CNA (GitHub)
Base Score 8.7 9.1
Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Attack Vector Network Network
Attack Complexity High Low
Privileges Required None None
User Interaction None None
Scope Changed Unchanged
Confidentiality Impact High High
Integrity Impact High High
Availability Impact None None
CVSSv3 Version 3.1 3.1
No SUSE Bugzilla entries cross referenced.

No SUSE Security Announcements cross referenced.

List of released packages

Product(s) Fixed package version(s) References


Status of this issue by product and package

Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.

Product(s) Source package State
Products past their end of life and not receiving proactive updates anymore.
SUSE Linux Enterprise Module for Package Hub 15 SP5 govulncheck-vulndb Affected
SUSE Linux Enterprise Module for Package Hub 15 SP6 govulncheck-vulndb Affected
openSUSE Leap 15.5 govulncheck-vulndb Affected
openSUSE Leap 15.6 govulncheck-vulndb Affected


SUSE Timeline for this CVE

CVE page created: Thu Jul 30 15:07:08 2026
CVE page last modified: Fri Jul 31 14:07:11 2026