Claude (Anthropic) Claude Fable 5.1 · Version Status
Claude (Anthropic) Claude Fable 5.1 End of Life Date
Claude (Anthropic) Claude Fable 5.1 end-of-life date, support status, and CVE risk. Data from endoflife.date and official vendor documentation.
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Claude (Anthropic) Claude Fable 5.1 is actively supported. EOL date: September 1, 2027.
📅 Get reminded before Claude (Anthropic) Claude Fable 5.1 reaches EOL on September 1, 2027 — alerts 90, 30 & 7 days out.
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EOL Date
Sep 1, 2027
365 days remaining
Latest Release
—
Standard release
Release Date
Sep 1, 2026
Claude (Anthropic) Claude Fable 5.1 series
Lifecycle detail
Claude (Anthropic) claude-fable-5-1 was released on September 1, 2026 and support is scheduled to end on September 1, 2027 — a planned supported lifespan of 1 year, in line with the 1 year and 1 month median for Claude (Anthropic) releases.
Attack Surface
20/30 High tier
CISA KEV Exposure
0/20 Not in 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 →
All Claude (Anthropic) Versions
What does Claude (Anthropic) Claude Fable 5.1 end of life mean?
When Claude (Anthropic) Claude Fable 5.1 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 Claude (Anthropic) Claude Fable 5.1 past its EOL date creates a permanently growing attack surface that standard security tooling will not surface.
Migrate to Claude (Anthropic) Claude Mythos 5.1 or implement compensating controls — network segmentation, enhanced monitoring, restricted access — while migration is underway.
Frequently Asked Questions
When does Claude (Anthropic) Claude Fable 5.1 reach end of life?
Claude (Anthropic) Claude Fable 5.1 reached end of life on September 1, 2027. That is 365 days remaining.
Is Claude (Anthropic) Claude Fable 5.1 still supported?
Yes, Claude (Anthropic) Claude Fable 5.1 is currently supported. The EOL date is September 1, 2027.
What should I upgrade to from Claude (Anthropic) Claude Fable 5.1?
The recommended upgrade from Claude (Anthropic) Claude Fable 5.1 is
Claude (Anthropic) Claude Mythos 5.1 — the latest actively supported version. Check the
Claude (Anthropic) full timeline for all supported versions.
What are the security risks of running Claude (Anthropic) Claude Fable 5.1 past EOL?
When Claude (Anthropic) Claude Fable 5.1 reaches end of life, the maintainers stop issuing security patches. Any CVEs disclosed after the EOL date accumulate with no remediation path. Most vulnerability scanners do not flag this — it is the CVE blind spot. Organizations running EOL Claude (Anthropic) should migrate immediately or implement compensating controls.