Security firm Xint has revealed a flaw in OpenAI's compaction feature that allows the extraction of a model's hidden reasoning processes in plain text. This feature normally shrinks long conversations to save space.
OpenAI's reasoning models typically process problems before providing answers, with the raw reasoning normally returned as an encrypted item inaccessible to users. The discovered method successfully bypassed these protections, exposing the internal thought processes of the AI.
Sources and references
Original report
OpenAI Compaction Flaw Let Researchers Bypass Hidden Reasoning Protections
The Hacker News
Read on The Hacker News (opens in a new tab)Ref 00Z1ZKVS
Cite this
APA
Interestana AI Editorial. (2026, October 27). OpenAI Compaction Flaw Exposed Hidden Reasoning Protections. Interestana. https://interestana.com/articles/openai-compaction-flaw-let-researchers-bypass-hidden-reasoning-protections-00z1zkvs
MLA
“OpenAI Compaction Flaw Exposed Hidden Reasoning Protections.” Interestana, 27 Oct. 2026, interestana.com/articles/openai-compaction-flaw-let-researchers-bypass-hidden-reasoning-protections-00z1zkvs.
Chicago
Interestana AI Editorial. “OpenAI Compaction Flaw Exposed Hidden Reasoning Protections.” Interestana, October 27, 2026. https://interestana.com/articles/openai-compaction-flaw-let-researchers-bypass-hidden-reasoning-protections-00z1zkvs.
BibTeX
@misc{interestana_00z1zkvs,
author = {{Interestana AI Editorial}},
title = {{OpenAI Compaction Flaw Exposed Hidden Reasoning Protections}},
howpublished = {Interestana},
year = {2026},
month = oct,
url = {https://interestana.com/articles/openai-compaction-flaw-let-researchers-bypass-hidden-reasoning-protections-00z1zkvs},
note = {Summary of reporting by The Hacker News, https://thehackernews.com/2026/10/openai-compaction-flaw-let-researchers.html}
}Credit the source
Original reporting: The Hacker News, “OpenAI Compaction Flaw Let Researchers Bypass Hidden Reasoning Protections”, https://thehackernews.com/2026/10/openai-compaction-flaw-let-researchers.html(opens in a new tab)
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