Mozilla Firefox and Thunderbird known exploited vulnerabilities
We track 7 CVEs in Mozilla Firefox and Thunderbird. All of them are on CISA's Known Exploited Vulnerabilities catalog, meaning CISA has evidence of exploitation in the wild (listed 2021–2023). The most recent is CVE-2016-9079, added to KEV on .
Also listed as: Firefox, Firefox ESR, and Thunderbird. CISA, NVD and vendor advisories name the same product differently; each CVE page keeps the wording from its source.
- CVEs tracked
- 7
- On CISA KEV
- 7
- Ransomware use
- 0
- Rated critical
- 1
Every Mozilla Firefox and Thunderbird CVE we track
| CVE / Vulnerability | Severity | CVSS | EPSS | Added to KEV | Patch by |
|---|---|---|---|---|---|
| CVE-2016-9079 Mozilla Firefox, Firefox ESR, and Thunderbird Use-After-Free Vulnerability | [ HIGH ] | 7.5 | 87.4% | ||
| CVE-2019-11708 Mozilla Firefox and Thunderbird Sandbox Escape Vulnerability | [ CRITICAL ] | 10.0 | 55.9% | ||
| CVE-2019-11707 Mozilla Firefox and Thunderbird Type Confusion Vulnerability | [ HIGH ] | 8.8 | 37.7% | ||
| CVE-2013-1690 Mozilla Firefox and Thunderbird Denial-of-Service Vulnerability | [ HIGH ] | 8.8 | 69.0% | ||
| CVE-2020-6820 Mozilla Firefox And Thunderbird Use-After-Free Vulnerability | [ HIGH ] | 8.1 | 7.1% | ||
| CVE-2020-6819 Mozilla Firefox And Thunderbird Use-After-Free Vulnerability | [ HIGH ] | 8.1 | 3.0% | ||
| CVE-2019-17026 Mozilla Firefox And Thunderbird Type Confusion Vulnerability | [ HIGH ] | 8.8 | 46.3% |
Sorted by date added to KEV. Severity and CVSS as stated by NVD or the vendor; EPSS from FIRST.org. "Patch by" is CISA's BOD 22-01 deadline for US federal agencies, a useful priority signal for everyone else. Machine-readable: /api/v1/vendors/mozilla.json.
Other Mozilla products
Every row links to its CVE record with the CISA required action, catalog coverage and primary sources. We describe impact and remediation only; no exploit code. See the full KEV tracker or compare KEV catalogs.