# CVE-2019-11707: Mozilla Firefox and Thunderbird Type Confusion Vulnerability

> CVE-2019-11707: Mozilla Firefox and Thunderbird Type Confusion Vulnerability. CVSS 8.8 (CVSS 3.1), in CISA KEV.

Canonical: https://rewindex.com/cve/CVE-2019-11707
Last updated: 2025-10-21T23:45:33Z

- Published: 2019-07-23 13:20 UTC · Updated: 2025-10-21 23:45 UTC · Assigner: mozilla
- CVSS: 8.8 (CVSS 3.1) · Severity: High · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- EPSS: 37.7%, 99th percentile (scored 2026-10-25)
- CISA KEV: yes, added 2022-05-23, federal due date 2022-06-13, ransomware use: Unknown

## Description

A type confusion vulnerability can occur when manipulating JavaScript objects due to issues in Array.pop. This can allow for an exploitable crash. We are aware of targeted attacks in the wild abusing this flaw. This vulnerability affects Firefox ESR \< 60.7.1, Firefox \< 67.0.3, and Thunderbird \< 60.7.2.

## CISA required action

Apply updates per vendor instructions.

## Affected vendors and products

- Mozilla: Firefox
- Mozilla: Firefox ESR
- Mozilla: Thunderbird

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2019-11707)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2019-11707)
- [https://bugzilla.mozilla.org/show\_bug.cgi?id=1544386](https://bugzilla.mozilla.org/show_bug.cgi?id=1544386)
- [https://security.gentoo.org/glsa/201908-12](https://security.gentoo.org/glsa/201908-12)
- [https://www.mozilla.org/security/advisories/mfsa2019-18/](https://www.mozilla.org/security/advisories/mfsa2019-18/)
- [https://www.mozilla.org/security/advisories/mfsa2019-20/](https://www.mozilla.org/security/advisories/mfsa2019-20/)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2019-11707 · Markdown: https://rewindex.com/cve/CVE-2019-11707.md · JSON: https://rewindex.com/api/v1/cves/CVE-2019-11707 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T03:09:02.629Z