# CVE-2025-62379: Open Redirect in reflex-dev/reflex

> Attackers can redirect users to malicious sites via the auth-codespace endpoint in Reflex when Codespaces environment variables are set.

- **Severity:** Low 3.1 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/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:** 15 Oct 2025
- **Updated:** 15 Oct 2025
- **Also known as:** GHSA-rfh5-c9h5-q8jm, PYSEC-2026-1868

## What is CVE-2025-62379?

CVE-2025-62379 is a low-severity vulnerability in reflex-dev reflex, published on 15 Oct 2025. 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

Reflex is a library to build full-stack web apps in pure Python. In versions 0.5.4 through 0.8.14, the /auth-codespace endpoint automatically assigns the redirect_to query parameter value directly to client-side links without any validation and triggers automatic clicks when the page loads in a GitHub Codespaces environment. This allows attackers to redirect users to arbitrary external URLs. The vulnerable route is only registered when a Codespaces environment is detected, and the detection is controlled by environment variables. The same behavior can be activated in production if the GITHUB_CODESPACES_PORT_FORWARDING_DOMAIN environment variable is set. The vulnerability occurs because the code assigns the redirect_to query parameter directly to a.href without any validation and immediately triggers a click (automatic navigation), allowing users to be sent to arbitrary external domains. The execution condition is based on the presence of a sessionStorage flag, meaning it triggers immediately on first visits or in incognito/private browsing windows, with no server-side origin/scheme whitelist or internal path enforcement defenses in place. This issue has been patched in version 0.8.15. As a workaround, users can ensure that GITHUB_CODESPACES_PORT_FORWARDING_DOMAIN is not set in a production environment.

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

## Which versions are affected by CVE-2025-62379?

3 open source packages ship an affected version, including reflex.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `reflex` | PyPI | From 0.5.4 to 0.8.14 | None |
| `reflex` | PyPI | From 0.5.4 to 0.8.14 | None |
| `reflex` | PyPI | From 0.5.4 to 0.8.14 | None |

## How do I fix CVE-2025-62379?

No fix has been published for CVE-2025-62379 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-62379 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-62379 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-62379 and fix it if it is affected.

What it is: CVE-2025-62379 is a low-severity vulnerability in reflex-dev reflex, published on 15 Oct 2025. 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-2025-62379 exists.

Affected packages and fixed versions:
- reflex (PyPI): affected from 0.5.4 up to 0.8.14; no fix listed
- reflex (PyPI): affected from 0.5.4 up to 0.8.14; no fix listed
- reflex (PyPI): affected from 0.5.4 up to 0.8.14; no fix listed

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-2025-62379/ (Markdown: https://insights.sbomify.com/CVE-2025-62379/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-62379
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-62379
- OSV: https://osv.dev/vulnerability/CVE-2025-62379

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-62379/
Summaries are generated and may contain mistakes; the official description above is the record.