# CVE-2026-85676: Dub Open Redirect via Unrestricted redir_url Parameter

> Attackers can redirect users to malicious sites via Dub short links by exploiting an unvalidated redir_url parameter, enabling phishing attacks.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA: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:** 4 Sep 2026
- **Updated:** 14 Sep 2026
- **Also known as:** GHSA-vpv7-5wp2-c8xx

## What is CVE-2026-85676?

CVE-2026-85676 is a medium-severity vulnerability in dubinc dub, published on 4 Sep 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

Dub contains an open redirect vulnerability in the redir_url query parameter that is accepted on every short link without validation or domain allowlist enforcement. Attackers can append the redir_url parameter to any short link to redirect visitors to arbitrary external URLs through the trusted Dub domain, bypassing destination blacklists and potentially enabling phishing attacks with link cloaking enabled.

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

## Which versions are affected by CVE-2026-85676?


## How do I fix CVE-2026-85676?

No fix has been published for CVE-2026-85676 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-85676 being exploited?

There is no known exploitation of CVE-2026-85676 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-85676 and fix it if it is affected.

What it is: CVE-2026-85676 is a medium-severity vulnerability in dubinc dub, published on 4 Sep 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-2026-85676 in the wild and no public exploit code.

Affected product: dubinc dub. 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-2026-85676/ (Markdown: https://insights.sbomify.com/CVE-2026-85676/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-85676
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-85676
- OSV: https://osv.dev/vulnerability/CVE-2026-85676

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-85676/
Summaries are generated and may contain mistakes; the official description above is the record.