# Study finds planted news can swing AI forecasts

_Published Wednesday, September 23, 2026 at 9:08 PM EDT · AI, Security, Science · Latest · Tier 2 — Notable_

Researchers found that articles planted in a news corpus could change the probabilities produced by AI forecasting systems, even when an attacker had no access to the models or their users' questions. In a preprint, they tested three forecasters built on open 7-8B models against 500 resolved ForecastBench questions and a 17.4M-article news corpus.

One generated article per question pushed 56% of forecasts across the 0.5 probability threshold. Five articles did so for 69-73% and worsened the Brier score, a measure of forecast accuracy, from 0.18 to 0.37. The researchers also reported bypasses for three defenses they tested.

## Sources

- [cs.AI updates on arXiv.org](https://arxiv.org/abs/2609.22246)

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Canonical: https://techandbusiness.org/newswire/NGCZATpFToOyVZacTJCjQp
Published: 2026-09-24T01:08:38.565Z
Story chronology: 2026-09-23T04:00:00.000Z
Retrieved: 2026-09-24T03:33:46.907Z
Publisher: Tech & Business (techandbusiness.org)