After dissing Anthropic for limiting Mythos, OpenAI restricts access to Cyber
Source: Hacker News
In Brief
Posted: 12:27 PM PDT · April 30, 2026
Image Credits: ChatGPT
After Sam Altman trash‑talked Anthropic for gatekeeping its cybersecurity tool Mythos by only releasing it to select users, he confirmed that OpenAI would be doing the same with its competing tool, Cyber.
Altman said in a post on X on Thursday that OpenAI will begin rolling out GPT‑5.5 Cyber “to critical cyber defenders” in the next few days. OpenAI has an application on its website where people submit information about their credentials and planned use in order to gain access.
Cyber can perform tasks such as:
- Penetration testing
- Vulnerability identification (and exploitation)
- Malware reverse engineering
The application implies it is intended as a toolkit to help companies find security holes and test defenses, though there are concerns it could be misused by malicious actors.
When Anthropic similarly restricted access to Mythos, Altman called the tactic fear‑based marketing. Some critics agreed, saying Anthropic’s rhetoric was overblown. Ironically, an unauthorized group reportedly managed to gain access to Mythos anyway.
OpenAI says it is working to make Cyber more widely available by consulting with the U.S. government and identifying more users with legitimate cybersecurity credentials, as detailed in its scaling‑trusted‑access announcement.