Firefox 153 End of Life Date
Firefox 153 end-of-life date, support status, and CVE risk. Data reconciled from official vendor documentation and endoflife.date at every build; the source of each date is on the product page.
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 153.5.0, published October 13, 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: A CVE-based scan does not show the ongoing accumulation of unpatched vulnerabilities in EOL software versions. Some scanners flag unsupported versions of common products, but coverage varies, and none of them give you the date in advance. Running Firefox 153 past its EOL date creates a growing attack surface that a clean scan result does not rule out.
Migrate to Firefox 153 or implement compensating controls — network segmentation, enhanced monitoring, restricted access — while migration is underway.