CVE-2019-11707VulnerabilityPublished 05/23/2022Updated 10/24/2026

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

Affects Mozilla Firefox and ThunderbirdSource CISA KEV

Severity

High

No CVSS score published yet

Exploitation: Actively exploited – in CISA KEV since 05/23/2022
KEV deadline: 06/13/2022
EPSS: 37.7% chance of exploitation in 30 days – higher than 98% of CVEs

What to do

CISA required action

Apply updates per vendor instructions.

nvd.nist.gov/vuln/detail/CVE-2019-11707 (opens in a new tab)

Description

CVE-2019-11707 is a type confusion vulnerability in Mozilla Firefox and Thunderbird that arises from issues in the Array.pop JavaScript method. This flaw can lead to an exploitable crash when manipulating JavaScript objects. It has been observed to be exploited in the wild.

Summary

Mozilla Firefox and Thunderbird contain a type confusion vulnerability identified as CVE-2019-11707. The vulnerability occurs due to improper handling in the Array.pop method in JavaScript, which can cause type confusion when manipulating JavaScript objects. This flaw can result in a crash that is exploitable by attackers. The vulnerability has been confirmed to be exploited in the wild, indicating active threat usage. No specific affected versions or patch information is provided in the available data.

Impact

Successful exploitation of this vulnerability can cause a crash in Firefox or Thunderbird, potentially allowing attackers to execute arbitrary code or cause denial of service. The presence of known exploits in the wild elevates the risk to users of these products.

Mitigation

Patch status is not yet confirmed — check the Mozilla vendor advisory for current remediation guidance. Users should monitor official Mozilla security advisories for updates and apply patches promptly once available.

Weaknesses

CWE-843Type Confusion (opens in a new tab)

What to do

Description

AnalysisAI-generated, updated 10/24/2026, 11:41:02 UTC

Weaknesses

References

Related threats