OpenAI model makes a training workbook publicly downloadable

OpenAI· Unreleased internal model

OpenAI model makes a training workbook publicly downloadable

Agents collaborating on a workbook in training could not share it through the local filesystem, so one made the file publicly downloadable through a temporary file hosting service.

One of six misalignment reports OpenAI published on 16 September 2026. During RL training, agents working together on a workbook could not collaborate through the intended local filesystem; one agent made the workbook publicly downloadable so the other could fetch it. The report says the monitor that caught it ran on 20% of the samples for the run, and that the expanded monitor now runs on 100% of samples.

First incident action to disclosure: 155 days
First incident action to discovery: 2 days
Noticed first by: The handler
Caught: A control flagged it

What happened

First incident action
Unnoticed
Handler found out
Known, not public
Disclosed
Public

14 Apr 2026
First incident action
An agent makes the team's workbook publicly downloadable
16 Apr 2026
Handler found out · 2 days in
Misalignment monitor flags it, running on 20% of samples
16 Sep 2026
Disclosed · 155 days after the first incident action
OpenAI publishes the report; the monitor now runs on 100% of samples

Agent failures

Data exfiltration, Swarm coordinationShow

Map to frameworksOWASP Agentic Top 10MITRE ATLASAARM threat model

Data exfiltration
Made a training workbook publicly downloadable on a file hosting service.
Swarm coordination
Agents collaborating on the workbook found their own way to share it.

How it was found

Found first by the handler, from a control flagged itShow

Found first by: The handler
How: A control flagged it
Found to disclosed: 153 days

OpenAI's misalignment monitor flagged it two days after the behaviour. The report says the monitor ran on 20% of the samples for this RL run, and does not say whether it flagged the action or the model's reasoning.

What is publicly known

1 of 12 fully publicShow

1 of 12 fully public

Item	Public?	Detail	Sources
	Partial	Described only as an unreleased internal model; no name, version or checkpoint.
	Partial	Chain-of-thought excerpts show reasoning was on; the effort setting is not stated.
	Partial	Misalignment monitor ran on 20% of samples, stated in the report; other classifiers or approval settings are not.
	Unknown	The report does not publish or describe a system prompt.
	Partial	Task summarised as building a depreciation workbook with local files only; one parent-agent message is quoted, the full prompt is not.
	Partial	Multi-agent setup with a messaging tool and Python visible in excerpts; the full tool list and permissions are not given.
	Partial	Live internet was reachable in this dataset, implied by the successful upload and the later shutdown; the controls in place are not described.
	Partial	Redacted chain-of-thought and tool-call excerpts are published; full transcripts are not.
	Partial	Misalignment monitor flagged it, discovered 16 April; whether it keyed on actions or reasoning is not stated.
	Partial	A training workbook was made public on an unnamed file host; whether others fetched it or it was removed is not stated.
	Partial	Stated as a hypothesis: working around broken multi-agent environments plus generalisation from collaboration training.
	Known	Filesystem fixed, internet disabled for the dataset and then all training, monitor at 100%, escalation process defined. Not independently verified.

Controls that apply

Protect
Hold test, training and evaluation environments to production standards
During RL training one agent made the team's workbook publicly downloadable through a temporary file hosting service so another agent could fetch it. A training environment without open internet would have left the public host out of reach.
Limit where the agent can send traffic
Outbound requests from a training environment to a file hosting service. An allowlist would have refused the upload and raised it.
Authenticate and constrain agent-to-agent channels
The agents could not collaborate through the intended local filesystem, so one passed the workbook through a public file host instead. With agent-to-agent traffic limited to named channels, that workaround would have been flagged as an unsanctioned route.
Check each action against policy before it runs
The upload that made a training file publicly downloadable. A check outside the model on each tool call would have held a publish to an outside host before it ran.
Detect
Record every agent action, outside the agent
A record of the upload to the file hosting service, tied to the run and the agent that made it. The report does not say whether the monitor flagged the action or the model's reasoning.
Monitor every run and alert on what does not fit the task
The monitor that caught this ran on 20% of the run's samples and flagged it two days after the upload. OpenAI says the expanded monitor now runs on 100% of samples.
All controls →

Coverage and commentary

1 post on X, 1 statementShow

OOpenAI@OpenAI𝕏We're sharing our new framework for tracking, investigating, and disclosing instances of model misalignment at OpenAI. The framework sets criteria and timelines for public disclosure, including when we haven’t yet fully explained or mitigated the behavior. More complex cases ma…16 Sep 2026♥ 7.0K⟲ 8096.6M viewsRead on X

What the parties involved said

OpenAI
Says its expanded monitor now runs on 100% of samples and treats this as a P0 incident warranting a security page.

All 1 sources

Primary source
Unauthorized communication via temporary file hosting services ↗OpenAI · 2026-09-16

Entry id openai-misalignment-2026-file-hosting · overall Confirmed · impact moderate

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