Is Firefox safe right now?
Nothing new in 90 days
No Firefox flaws have been added to CISA's exploited list in the last 90 days (the most recent was Oct 6, 2025). Keep automatic updates on: that can change any day.
0exploited in the last 30 days
0in the last 90 days
0zero-days in 2026
13on CISA's list, all time
Earlier exploited flaws
- Mozilla Multiple Products Remote Code Execution Vulnerability
- Mozilla Firefox Use-After-Free Vulnerability Zero-day
- Mozilla Firefox, Firefox ESR, and Thunderbird Use-After-Free Vulnerability
- Mozilla Firefox Security Feature Bypass Vulnerability
- Mozilla Firefox and Thunderbird Sandbox Escape Vulnerability
- Mozilla Firefox and Thunderbird Type Confusion Vulnerability
- Mozilla Firefox and Thunderbird Denial-of-Service Vulnerability
- Mozilla Firefox Use-After-Free Vulnerability Zero-day
- Mozilla Firefox Use-After-Free Vulnerability Zero-day
- Mozilla Firefox Information Disclosure Vulnerability
- Mozilla Firefox And Thunderbird Use-After-Free Vulnerability
- Mozilla Firefox And Thunderbird Use-After-Free Vulnerability
- Mozilla Firefox And Thunderbird Type Confusion Vulnerability
By year
| Year | Exploited flaws added | Zero-days |
|---|---|---|
| 2026 (so far) | 0 | 0 |
| 2025 | 1 | 0 |
| 2024 | 1 | 1 |
| 2023 | 1 | 0 |
| 2022 | 7 | 2 |
Questions
Is Firefox safe right now?
No Firefox flaws have been added to CISA's exploited list in the last 90 days (the most recent was Oct 6, 2025). Keep automatic updates on: that can change any day. Confirm with the vendor's own advisories and install updates as soon as they're available.
How many Firefox vulnerabilities have been exploited?
13 flaws are on CISA's list of vulnerabilities known to be exploited in real attacks, 1 of them used by ransomware.
Covers products matching firefox, mozilla. Sources: CISA's Known Exploited Vulnerabilities catalog and the vendors' own advisories. Updated every hour. General information only; confirm details with the vendor.