# CVE-2026-35404: Open edX Platform has an Open Redirect in Survey Views via Unvalidated redirect_url Parameter

> Attackers can redirect authenticated Open edX users to malicious sites via unvalidated parameters, enabling phishing and credential theft.

- **Severity:** Medium 4.7 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/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:** 6 Apr 2026
- **Updated:** 11 May 2026
- **Also known as:** GHSA-2843-x998-f8r2

## What is CVE-2026-35404?

CVE-2026-35404 is a medium-severity vulnerability in openedx-platform, published on 6 Apr 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

Open edX Platform enables the authoring and delivery of online learning at any scale. The view_survey endpoint accepts a redirect_url GET parameter that is passed directly to HttpResponseRedirect() without any URL validation. When a non-existent survey name is provided, the server issues an immediate HTTP 302 redirect to the attacker-controlled URL. Additionally, the same unvalidated URL is embedded in a hidden form field and returned in a JSON response after form submission, where client-side JavaScript performs location.href = url. This enables phishing and credential theft attacks against authenticated Open edX users. This vulnerability is fixed with commit 76462f1e5fa9b37d2621ad7ad19514b403908970.

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

## Which versions are affected by CVE-2026-35404?

It affects 1 product.


Products: Openedx Openedx.

## How do I fix CVE-2026-35404?

No fix has been published for CVE-2026-35404 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-35404 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-35404 exists.

## Other vulnerabilities in openedx-platform

- [CVE-2026-42858](https://insights.sbomify.com/CVE-2026-42858/): Open edX Platform: Server-Side Request Forgery (SSRF) in SAML Provider Data Sync Endpoint (high 8.5)
- [CVE-2024-43782](https://insights.sbomify.com/CVE-2024-43782/): openedx-translations's Atlas translations for Open edX missing validation (high 7.7)
- [CVE-2026-42857](https://insights.sbomify.com/CVE-2026-42857/): Open edX Platform: Stored CSS Injection in Email Notifications via Incomplete HTML Sanitization (medium 4.6)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-35404 and fix it if it is affected.

What it is: CVE-2026-35404 is a medium-severity vulnerability in openedx-platform, published on 6 Apr 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: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-35404 exists.

Affected product: openedx-platform. 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-2026-35404/ (Markdown: https://insights.sbomify.com/CVE-2026-35404/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-35404
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-35404
- OSV: https://osv.dev/vulnerability/CVE-2026-35404

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-35404/
Summaries are generated and may contain mistakes; the official description above is the record.