Mozilla Firefox vulnerabilities: known CVEs & security history
Mozilla · Browser · 207 tracked CVEs · 0 actively exploited · updated July 2026 · what is a CVE? →
This is the full list of known vulnerabilities (CVEs) across all Mozilla Firefox release lines — 207 in total. A CVE here doesn't mean your version is affected — check Mozilla Firefox's current status and the safe version to run.
Known Mozilla Firefox CVEs
Actively-exploited and most-severe first. Showing the top 80 of 207. Open any CVE for full details.
| CVE | Severity | CVSS | EPSS | Year |
|---|---|---|---|---|
| CVE-2026-16367 | critical | 10 | 0% | 2026 |
| CVE-2026-4692 | critical | 10 | 0% | 2026 |
| CVE-2026-4689 | critical | 10 | 1% | 2026 |
| CVE-2026-4688 | critical | 10 | 1% | 2026 |
| CVE-2026-2778 | critical | 10 | 0% | 2026 |
| CVE-2026-2776 | critical | 10 | 0% | 2026 |
| CVE-2026-2768 | critical | 10 | 0% | 2026 |
| CVE-2026-2761 | critical | 10 | 0% | 2026 |
| CVE-2026-2760 | critical | 10 | 0% | 2026 |
| CVE-2026-0881 | critical | 10 | 0% | 2026 |
| CVE-2026-16412 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16411 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16410 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16408 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16407 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16402 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16395 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16389 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16388 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16387 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16383 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16382 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16377 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16375 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16369 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16368 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16363 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16361 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16360 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16358 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16357 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16356 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16355 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16353 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16352 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16351 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16350 | critical | 9.8 | 0% | 2026 |
| CVE-2026-16349 | critical | 9.8 | 0% | 2026 |
| CVE-2026-14241 | critical | 9.8 | 0% | 2026 |
| CVE-2026-12293 | critical | 9.8 | 0% | 2026 |
| CVE-2026-8401 | critical | 9.8 | 0% | 2026 |
| CVE-2026-8094 | critical | 9.8 | 0% | 2026 |
| CVE-2026-8091 | critical | 9.8 | 0% | 2026 |
| CVE-2026-6748 | critical | 9.8 | 0% | 2026 |
| CVE-2026-5735 | critical | 9.8 | 0% | 2026 |
| CVE-2026-5734 | critical | 9.8 | 0% | 2026 |
| CVE-2026-5731 | critical | 9.8 | 0% | 2026 |
| CVE-2026-4729 | critical | 9.8 | 0% | 2026 |
| CVE-2026-4721 | critical | 9.8 | 0% | 2026 |
| CVE-2026-4720 | critical | 9.8 | 0% | 2026 |
| CVE-2026-4700 | critical | 9.8 | 0% | 2026 |
| CVE-2026-4698 | critical | 9.8 | 1% | 2026 |
| CVE-2026-4696 | critical | 9.8 | 0% | 2026 |
| CVE-2026-4691 | critical | 9.8 | 0% | 2026 |
| CVE-2026-2807 | critical | 9.8 | 0% | 2026 |
| CVE-2026-2799 | critical | 9.8 | 0% | 2026 |
| CVE-2026-2797 | critical | 9.8 | 0% | 2026 |
| CVE-2026-2796 | critical | 9.8 | 1% | 2026 |
| CVE-2026-2795 | critical | 9.8 | 0% | 2026 |
| CVE-2026-2793 | critical | 9.8 | 0% | 2026 |
| CVE-2026-2792 | critical | 9.8 | 0% | 2026 |
| CVE-2026-2777 | critical | 9.8 | 0% | 2026 |
| CVE-2026-2775 | critical | 9.8 | 1% | 2026 |
| CVE-2026-2774 | critical | 9.8 | 1% | 2026 |
| CVE-2026-2773 | critical | 9.8 | 1% | 2026 |
| CVE-2026-2772 | critical | 9.8 | 0% | 2026 |
| CVE-2026-2771 | critical | 9.8 | 0% | 2026 |
| CVE-2026-2770 | critical | 9.8 | 0% | 2026 |
| CVE-2026-2767 | critical | 9.8 | 0% | 2026 |
| CVE-2026-2766 | critical | 9.8 | 0% | 2026 |
| CVE-2026-2765 | critical | 9.8 | 0% | 2026 |
| CVE-2026-2764 | critical | 9.8 | 0% | 2026 |
| CVE-2026-2763 | critical | 9.8 | 0% | 2026 |
| CVE-2026-2762 | critical | 9.8 | 1% | 2026 |
| CVE-2026-2759 | critical | 9.8 | 0% | 2026 |
| CVE-2026-2758 | critical | 9.8 | 0% | 2026 |
| CVE-2026-2757 | critical | 9.8 | 0% | 2026 |
| CVE-2026-0879 | critical | 9.8 | 1% | 2026 |
| CVE-2026-12297 | critical | 9.6 | 0% | 2026 |
| CVE-2026-12296 | critical | 9.6 | 0% | 2026 |
127 older / lower-severity CVEs not shown — see Mozilla Firefox's full record.
Is my Mozilla Firefox version affected?
The list above spans every release. To know whether your version is affected — and the minimum safe version to upgrade to — check it directly.
Check your Mozilla Firefox version → · Monitor Mozilla Firefox for new CVEs →
Mozilla Firefox vulnerabilities — frequently asked
How many known vulnerabilities does Mozilla Firefox have?
IsItPatched tracks 207 CVEs for Mozilla Firefox. 92 are critical-severity and 91 high-severity. These span every release line — what matters is whether the version you run is affected.
Does Mozilla Firefox have any actively-exploited vulnerabilities?
None of Mozilla Firefox's tracked CVEs are currently in CISA's KEV catalog — but new ones can be added at any time, so keep your version current.
What is the most severe Mozilla Firefox vulnerability?
Among tracked issues, CVE-2026-16367 (CRITICAL, CVSS 10) ranks highest — a Memory corruption weakness.
Is Mozilla Firefox safe to use?
It depends on the version. The latest supported Mozilla Firefox release (153.0) clears the known issues; older versions may still be affected. Check the exact version you run for a verdict.
CVE data aggregated from NVD, CISA KEV and EPSS (FIRST.org). Related: Mozilla Firefox security status · Mozilla Firefox end-of-life · actively-exploited CVEs. Always verify against Mozilla's advisories — see our disclaimer.