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

> Attackers can redirect authenticated users to malicious sites via crafted links, enabling phishing or credential theft in OpenShift environments.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 1 Oct 2026
- **Updated:** 29 Oct 2026
- **Also known as:** GHSA-8c7h-7vm9-jhj3

## What is CVE-2026-83589?

CVE-2026-83589 is a medium-severity vulnerability in Red Hat OpenShift Container Platform 4.12, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official 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.

Weakness: CWE-601 (URL Redirection to Untrusted Site)

## Which versions are affected by CVE-2026-83589?


## How do I fix CVE-2026-83589?

No fix has been published for CVE-2026-83589 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-83589 being exploited?

There is no known exploitation of CVE-2026-83589 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-83589 and fix it if it is affected.

What it is: CVE-2026-83589 is a medium-severity vulnerability in Red Hat OpenShift Container Platform 4.12, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-83589 in the wild and no public exploit code.

Affected product: Red Hat OpenShift Container Platform 4.12. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-83589/ (Markdown: https://insights.sbomify.com/CVE-2026-83589/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-83589
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-83589
- OSV: https://osv.dev/vulnerability/CVE-2026-83589

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-83589/
Summaries are generated and may contain mistakes; the official description above is the record.