Today · release, October 23

Moonshot drops cyber data to open Kimi; its test is private

Moonshot removes cyber-security training data to open Kimi K3.1 Pro's weights; on Moonshot's own exploit test the unfiltered model solves 90.5% of tasks and the release 81.0%

Concept illustration: a large monitor on a stand sits on a table, and its screen shows, from left to right, a laptop displaying a speech bubble on top of a stack of four flat slabs, one of them red; a ribbed waste bin with a red folder tilted into its opening, linked by a line to a label reading CYBER DATA; a second laptop displaying a speech bubble on a stack of three grey and beige slabs, pointed to by a label reading KIMI K3.1 PRO; and an open door in a dark frame, pointed to by a label reading OPEN WEIGHTS. Outside the screen on the right, a label reading MOONSHOT points by a line to the monitor's right edge.

Why it matters: How much attack capability an open-weight model carries is set by each lab. The sources read today show no common standard.

Moonshot removed cyber-security training data to release Kimi K3.1 Pro's open weights; on Moonshot's own unpublished exploit test, the unfiltered version of the same model solved 90.5% and the released version 81.0% (Moonshot, 2026-10-23). The same day, Artificial Analysis's cyber-defense index ranked DeepSeek V4.1 Flash 1017, which didn't refuse, first among publicly available models (Artificial Analysis, 2026-10-23). The two scores measure different capabilities.

Not proven yet: 90.5% and 81.0% come from Moonshot's own unpublished test How we checked →

Judgment update: Our read: open-weight models carry different levels of risk, so attack capability has to be checked lab by lab. Moonshot deliberately removed data to lower the released version's attack capability, and says the release trails the closed frontier by at least three months, without naming the model it compares against. DeepSeek's model ranks first on the defense test, and part of that score comes from not refusing. Epoch AI, a research group that tracks AI capability progress, estimated the same day with a cyber version of its capabilities index that the strongest open-weight model, Zhipu's GLM-5.3, roughly matches the closed frontier of six to seven months earlier (Epoch AI, 2026-10-23). That estimate maps scores onto the release dates of closed models, a different method from Moonshot's "at least three months," so the two figures can't be compared directly. Epoch's newsletter doesn't say whether the estimate includes K3.1 Pro or DeepSeek V4.1 Flash 1017, and Epoch's same-day release page on its site hasn't been reviewed. This reading currently rests only on Moonshot's own account and one reading each from two organizations. What would prove this wrong: after Kimi K3.1 Pro's weights are released, third-party cyber-security measurements show the released version has caught up with the closed frontier.

Source and checks

This item ran in the brief of Oct 24, 2026, alongside 11 other items. How we checked it, the quote checks and what was still missing that day are on that issue's How we checked page.

Cite this item

SecondSource (2026). "Moonshot drops cyber data to open Kimi; its test is private." https://secondsource.io/en/news/2026-10-24-2/. Accessed access date.