Mozilla Firefox and Thunderbird Type Confusion Vulnerability

Are you affected?

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• cpe mozilla/firefoxversion unspecified
• cpe mozilla/thunderbirdversion unspecified
• vendor Mozilla Firefox and Thunderbirdversion unspecified

How to fix CVE-2019-11707

• Recommended remediation

  Apply updates per vendor instructions. CISA due date Jun 13, 2022.

• Official advisories

  • CISA KEV · cisa.gov
  • CVE.org · cve.org
  • FIRST EPSS · first.org
  • NIST NVD · nvd.nist.gov
  • VulnCheck KEV · vulncheck.com

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

1. Jul 23, 2019 · Catalog

   Detected

   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.

2. May 23, 2022 · CISA KEV

   Known exploited

   Apply updates per vendor instructions.

3. Jun 13, 2022 · CISA KEV

   Remediation due

   Apply updates per vendor instructions.

4. Jun 16, 2026 · Catalog

   Updated

   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.

Sources

• CISA KEVConfirmed exploitationCVE-2019-11707

  Mozilla Firefox and Thunderbird contain a type confusion vulnerability that can occur when manipulating JavaScript objects due to issues in Array.pop, allowing for an exploitable crash.

  cisa.gov
• CVE.orgVulnerability recordCVE-2019-11707

  Official CVE identifier

  cve.org
• FIRST EPSSExploitation probabilityCVE-2019-11707

  30-day exploitation probability 37.7%

  first.org
• Exploit DatabasePublic exploit reference47038

  Public archive entry. The exploit body is not stored here.

  exploit-db.com
• Exploit DatabasePublic exploit reference50691

  Public archive entry. The exploit body is not stored here.

  exploit-db.com
• NIST NVDVulnerability recordCVE-2019-11707

  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, an

  nvd.nist.gov
• VulnCheck KEVConfirmed exploitationCVE-2019-11707

  Mozilla Firefox and Thunderbird contain a type confusion vulnerability that can occur when manipulating JavaScript objects due to issues in Array.pop, allowing for an exploitable crash.

  vulncheck.com

References

• Issue Tracking · bugzilla.mozilla.org
• VulnCheck exploitation evidence · docs.google.com
• CISA note · nvd.nist.gov
• Third Party Advisory · security.gentoo.org
• VulnCheck exploitation evidence · cisa.gov
• Vendor Advisory · mozilla.org
• Vendor Advisory · mozilla.org

Freshness

Last verified in this catalog Oct 17, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.