Become a TechRadar Insider
- OpenAI introduces GPT‑5.5‑Cyber following uproar around Anthropic Mythos
- It's a modest upgrade focused on permissive cybersecurity tasks like vuln triage and malware analysis
- Access is limited to vetted teams in the Trusted Access for Cyber (TAC) program, unlike Anthropic’s more restricted Mythos Preview
OpenAI has introduced GPT-5.5-Cyber, an upgraded cybersecurity model looking to take some of the shine off Anthropic's Mythos Preview release.
Coming less than a month after the launch of GPT-5.4-Cyber, this is not a major upgrade by any means, and users should not expect many changes, OpenAI explained.
instead, users should expect a model trained to be more permissive when it comes to cybersecurity tasks, making it easier to use for things like vulnerability identification, triage, patch validation, and malware analysis.
Competing with Mythos
“GPT‑5.5‑Cyber lets a smaller set of partners study advanced workflows where specialized access behavior may matter,” OpenAI said in a blog post.
“The cyber defense ecosystem is broad, and GPT‑5.5 and GPT‑5.5‑Cyber play different roles in meeting the needs of organizations and researchers across it, depending on the task, the setting, and the safeguards around how the model is used. For most teams, GPT‑5.5 with TAC is our strongest broadly useful model for legitimate defensive work, with strong safeguards against misuse.”
As with the previous version, this edition will only be given only to vetted cybersecurity teams. However, unlike its key competitor - Mythos, which was given to only a handful of companies, OpenAI’s model will be offered to a broader set of users, members of the Trusted Access for Cyber (TAC) program.
Back when it introduced GPT-5.4-Cyber, OpenAI said it was scaling TAC to “thousands of verified individual defenders and hundreds of teams responsible for defending critical software."
Anthropic first disclosed Project Glasswing in early April 2026, saying that the AI model Mythos Preview was too powerful to be given freely. Apparently, it was able to surface decades-old vulnerabilities in some of the most widely-used operating systems in existence, and chain them together to create working exploits.
➡️ Read our full guide to the best antivirus
1. Best overall:
Bitdefender Total Security
2. Best for families:
Norton 360 with LifeLock
3. Best for mobile:
McAfee Mobile Security
Follow TechRadar on Google News and add us as a preferred source to get our expert news, reviews, and opinion in your feeds.