OpenAI says new GPT-5.5-Cyber outperforms Anthropic's Mythos on cybersecurity benchmark
OpenAI's GPT-5.5-Cyber just beat Anthropic's Mythos on cybersecurity benchmarks. The real play: shifting from finding vulnerabilities to patching them automatically.
Why it matters
OpenAI is expanding beyond general-purpose models into specialized cybersecurity AI, positioning itself against Anthropic while building a 25+ firm partner network. This signals a strategic pivot from vulnerability detection to autonomous remediation—a higher-value capability.
The key facts
14 to knowGPT-5.5-Cyber model released
Outperforms Anthropic's Mythos on cybersecurity benchmark
Daybreak cybersecurity initiative expanded
Codex Security plugin updated
25+ security firms and several governments in partner network
Shift from vulnerability finding to automatic patching
Published June 23, 2026 (future date — UNVERIFIED)
GPT-5.5-Cyber model release (specialized cybersecurity variant)
Claimed performance advantage over Anthropic's Mythos on cybersecurity benchmark
Daybreak cybersecurity initiative expansion
Updated Codex Security plugin
Partner network: 25+ security firms and multiple governments
Strategic shift: vulnerability finding → automated patching
UNVERIFIED: No third-party benchmark confirmation cited; claim appears in company announcement
Go to the source
The Decoderthe-decoder.com
Publisher excerpt: OpenAI is expanding its Daybreak cybersecurity initiative with an updated Codex Security plugin, the full GPT-5.5-Cyber model, and a partner network with more than 25 security firms and several governments. The focus shifts from finding vulnerabilities to patching them automatically.