# Security Researchers Hacked OpenAI Using Claude

> Security researchers exploited a flaw in OpenAI's forum to take over employee ChatGPT accounts via Anthropic's Claude.
- Title: Security Researchers Hacked OpenAI Using Claude · PCMAG
- Summary: Security researchers exploited a flaw in OpenAI's forum to take over employee ChatGPT accounts via Anthropic's Claude. Hackers used Claude Opus 5 to breach…
- Keywords: hacktron, openai, anthropic, claude, chatgpt, codex, discourse, bug bounty, heif heist, ai security, technology, Security
- Source: PCMAG — https://pcmag.com/news/security-researchers-hacked-openai-using-anthropics-claude
- Author: Bee Wertheimer
- Published: 2026-09-18T17:59:12+00:00
- Read time: 1 min
- Topics: hacktron, openai, anthropic, claude, chatgpt, codex, discourse, bug bounty, heif heist, ai security, technology
## Researchers hacked OpenAI
Security researchers used Anthropic's Claude to breach OpenAI's employee ChatGPT accounts via a Discourse forum flaw.

> Until two months ago, any user or OpenAI employee logging into OpenAI's own help forum could have had their ChatGPT and Codex accounts taken over.
## How the hack worked
Hackers exploited a Discourse forum vulnerability to access GitHub, Slack, and email systems through connected services.

> Since people can connect various services to Codex and ChatGPT, the scope of what we could theoretically access was huge, including GitHub, Slack, and emails.
## Claude Opus 5 enabled breach
The hack required Anthropic's Claude Opus 5, which produced an exploit that earlier versions couldn't generate.
## 24-hour fix
OpenAI and Discourse resolved the vulnerability within 24 hours after researchers reported the flaw.
## Bug bounty paid
Hacktron received a $6,500 reward from OpenAI for identifying and fixing the security flaw.
## Key takeaway

Hackers used Claude Opus 5 to breach OpenAI within days, highlighting AI security risks.