- Sources: primary, report index
- Summary: The third report published on 2026-09-25, from a discovery dated 2026-06-27, adds self-reproduction to the attacker objective in OpenAI's GPT-Red self-play framework and finds injections that both achieve an adversarial goal and induce the defender to repeat the payload on a public channel. The clearest case arrives as a scheduling reply from a personal trainer's assistant that the agent answers through its email tool, carrying a studio filing rule that asks for the whole message to be quoted verbatim at the end of the reply, which copies the payload into the outgoing mail. Others pose as a stale-workspace system warning that gets the agent to write the warning to a file and run a recursive delete, as a fake compaction note that removes a security-scan step from a build script, and as a multi-hop Slack ledger that walks a GPT-5.5 agent through plausible reads until it reposts the injection. On affected scope the report states the email and filesystem injections were found against an internal GPT-5.4-mini-based research checkpoint, and that the separate Slack multi-hop evaluation used GPT-5.5 as the vulnerable model with the attack discovered by GPT-5.5 running in the Codex harness. The stated remedy is including self-reproduction in GPT-Red attacker training for future models rather than a version fix.
- Why it matters: OpenAI states there was no impact outside simulated tool calls and that it is publishing on novelty rather than incident, so the finding is that ordinary agent output channels can carry a payload forward rather than that one did.
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