2 min readApr 15, 2026 09:27 AM ISTOpenAI, creator of popular chatbot ChatGPT, said that GPT-5.4-Cyber will initially be rolled out on a limited basis to vetted security vendors, organizations and researchers because of its more permissive design. (Express Image).OpenAI on Tuesday unveiled GPT-5.4-Cyber, a variant of its latest flagship model fine-tuned specifically for defensive cybersecurity work, following rival Anthropic’s announcement of frontier AI model Mythos.Mythos, announced on April 7, is being deployed as part of Anthropic’s “Project Glasswing”, a controlled initiative under which select organizations are permitted to use the unreleased Claude Mythos Preview model for defensive cybersecurity purposes. It has found “thousands” of major vulnerabilities in operating systems, web browsers and other software.OpenAI, creator of popular chatbot ChatGPT, said that GPT-5.4-Cyber will initially be rolled out on a limited basis to vetted security vendors, organizations and researchers because of its more permissive design.The company is also expanding its Trusted Access for Cyber program to thousands of verified individual defenders and hundreds of teams protecting critical software, it said in a post on its website.OpenAI is adding new tiers to its TAC program, which was launched in February, with higher levels of verification unlocking more powerful capabilities.Users approved for the highest tier will gain access to GPT-5.4-Cyber, which has fewer restrictions on sensitive cybersecurity tasks such as vulnerability research and analysis. Tags:OpenaiAdvertisementLoading Recommendations...Apr 15: Latest News01Heart specialist shares case of 37-year-old man who, despite running 5 km every day, eating no junk, needed two stents: ‘If your father/uncle had…’02Why AFI wants to vet athletes’ contracts with sponsors0314 killed, 19 injured in boiler blast at Vedanta plant in Chhattisgarh04Amendment to Nari Shakti Vandan Act: BJP’s women cadre ready to contest next Lok Sabha polls in Pune, says Medha Kulkarni05Disney to eliminate 1,000 positionsLive BlogBIE AP Inter Results 2026, Bie.ap.gov.in LIVE Updates: Over 9 lakh Intermediate 1st, 2nd year students await their marks memo3 minutes agoDhurandhar 2 Box Office Collection Day 27 LIVE: Aditya Dhar’s franchise surpasses Pushpa and Baahubali, becomes first Indian franchise to cross Rs 3,000 crore worldwide3 minutes agoAP Inter 1st 2nd Year Results 2026, Resultsbie.ap.gov.in LIVE Updates: How can I download my marks memo at bie.ap.gov.in?4 minutes agoMP Board 10th 12th Result 2026 Live Updates: CM Mohan Yadav to declare results today at mpbse.mponline.gov.in7 minutes agoMPBSE MP Board Result 2026 Live Updates: Class 10th, 12th results to be announced at mpbse.mponline.gov.in8 minutes ago