Firefox 158 · Version Status

Firefox 158 End of Life Date

Firefox 158 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 158 reaches end of life on October 27, 2026. Plan your migration now — 13 days remaining.
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EOL Date
Oct 27, 2026
13 days remaining
Latest Release
158.0
Standard release
Release Date
Oct 13, 2026
Firefox 158 series
Lifecycle detail

Firefox 158 was released on October 13, 2026 and support is scheduled to end on October 27, 2026 — a planned supported lifespan of 14 days, shorter than the 28 days median for Firefox releases. It is not an LTS release; Firefox reserves longer patch windows for its LTS versions. Its most recent patch is 158.0, published October 13, 2026.

← Firefox 157 All Firefox versions
55 / 100
High Risk
EOL Risk Score™  How is this calculated? →
EOL Recency
15/40
Attack Surface
10/30 Medium tier
CISA KEV Exposure
20/20 Named in CISA KEV
Extended Support
10/10 None available
EOL Risk Score™ — proprietary methodology by endoflife.ai. Factors: EOL recency, attack surface breadth, CISA KEV catalog presence, extended support availability. Updated at every build. Methodology →  ·  View score card →
Recommended upgrade path
Firefox 153
Latest release: 153.5.0 · EOL: Supported
View full Firefox timeline →
All Firefox Versions
VersionLatestEOL DateStatus
78 LTS 78.15.0 Nov 2, 2021 EOL
91 LTS 91.13.0 Sep 20, 2022 EOL
102 LTS 102.15.1 Sep 26, 2023 EOL
103 103.0.2 Aug 23, 2022 EOL
104 104.0.2 Sep 20, 2022 EOL
105 105.0.3 Oct 18, 2022 EOL
106 106.0.5 Nov 15, 2022 EOL
107 107.0.1 Dec 13, 2022 EOL

What does Firefox 158 end of life mean?

When Firefox 158 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 158 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.

Frequently Asked Questions
When does Firefox 158 reach end of life?
Firefox 158 reaches end of life on October 27, 2026. That is 13 days remaining.
Is Firefox 158 still supported?
Firefox 158 is still supported but approaching end of life on October 27, 2026. Begin planning your migration now.
What should I upgrade to from Firefox 158?
The recommended upgrade from Firefox 158 is Firefox 153 — the latest actively supported version. Check the Firefox full timeline for all supported versions.
What are the security risks of running Firefox 158 past EOL?
When Firefox 158 reaches end of life, the maintainers stop issuing security patches. Any CVEs disclosed after the EOL date accumulate with no vendor fix. A CVE-based scan does not show this — it is the CVE blind spot; some scanners flag unsupported versions of common products, but coverage varies and none give the date in advance. Organizations running EOL Firefox should migrate immediately or implement compensating controls.
Deep Dive
Full guide
Firefox ESR End of Life & Support Options: What To Do When ESR Patches Stop (140 ESR Ends September 29, 2026; 153 ESR Current)
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Data from endoflife.date API · Generated at build time · How we source data →