Claude (Anthropic) Claude Sonnet 4.5 · Version Status
Claude (Anthropic) Claude Sonnet 4.5 End of Life Date
Claude (Anthropic) Claude Sonnet 4.5 end-of-life date, support status, and CVE risk. Data from endoflife.date and official vendor documentation.
⚡
Claude (Anthropic) Claude Sonnet 4.5 reaches end of life on September 29, 2026. Plan your migration now — 51 days remaining.
📅 Get reminded before Claude (Anthropic) Claude Sonnet 4.5 reaches EOL on September 29, 2026 — alerts 90, 30 & 7 days out.
EOL Date
Sep 29, 2026
51 days remaining
Latest Release
—
Standard release
Release Date
Sep 29, 2025
Claude (Anthropic) Claude Sonnet 4.5 series
Lifecycle detail
Claude (Anthropic) claude-sonnet-4-5-20250929 was released on September 29, 2025 and support is scheduled to end on September 29, 2026 — 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 Sonnet 4.5 end of life mean?
When Claude (Anthropic) Claude Sonnet 4.5 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 Sonnet 4.5 past its EOL date creates a permanently growing attack surface that standard security tooling will not surface.
Migrate to Claude (Anthropic) Claude Opus 5 or implement compensating controls — network segmentation, enhanced monitoring, restricted access — while migration is underway.
Frequently Asked Questions
When does Claude (Anthropic) Claude Sonnet 4.5 reach end of life?
Claude (Anthropic) Claude Sonnet 4.5 reached end of life on September 29, 2026. That is 51 days remaining.
Is Claude (Anthropic) Claude Sonnet 4.5 still supported?
Claude (Anthropic) Claude Sonnet 4.5 is still supported but approaching end of life on September 29, 2026. Begin planning your migration now.
What should I upgrade to from Claude (Anthropic) Claude Sonnet 4.5?
The recommended upgrade from Claude (Anthropic) Claude Sonnet 4.5 is
Claude (Anthropic) Claude Opus 5 — 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 Sonnet 4.5 past EOL?
When Claude (Anthropic) Claude Sonnet 4.5 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.