Firefox 153 End of Life Date
Firefox 153 end-of-life date, support status, and CVE risk. Data from endoflife.date and official vendor documentation.
Firefox 153 was released on July 21, 2026 and has no published end-of-life date yet. It is a long-term support (LTS) release, so it carries a longer patch window than the interim releases around it. Its most recent patch is 153.2.0, published September 1, 2026.
What does Firefox 153 end of life mean?
When Firefox 153 reaches end of life, the maintainers stop issuing security patches for this version. CVEs discovered after the EOL date are publicly disclosed on the National Vulnerability Database with no patch available. Exploit code frequently appears on GitHub within days of disclosure.
The CVE blind spot: Most vulnerability scanners check for known CVEs but do not flag the ongoing accumulation of unpatched vulnerabilities in EOL software versions. Running Firefox 153 past its EOL date creates a permanently growing attack surface that standard security tooling will not surface.
Migrate to Firefox 155 or implement compensating controls — network segmentation, enhanced monitoring, restricted access — while migration is underway.