CVE-2026-35404
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedOpen 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysisThe application redirects the browser to a URL taken from user input without validating it, so an attacker can craft a link on your trusted domain that quietly bounces victims to a malicious site. It is a staple of phishing and token theft. The fix is to allow-list redirect destinations or use indirect reference keys, never a raw user-supplied URL.
General guidance for the open redirect class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data<= 2026-04-02CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedPull the latest code from the Open edX master branch or the release branch containing commit 76462f1e5fa9b37d2621ad7ad19514b403908970
- Locate the vulnerable view_survey endpoint in your Open edX installation (typically in lms/djangoapps/survey or similar location)
- Identify the code that handles the redirect_url GET parameter
- Apply the fix from commit 76462f1e5fa9b37d2621ad7ad19514b403908970 which adds URL validation before using redirect_url in HttpResponseRedirect()
- Verify the fix ensures redirect_url is validated (e.g., check it's a relative URL or belongs to an allowed domain) before redirecting
- Test the patched endpoint with both valid and invalid redirect_url values, including malicious external URLs
- Ensure the JSON response and hidden form field also validate the URL before embedding it
Generated from the published advisory — verify against the referenced sources before acting.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-35404 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-35404 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data