Evidence

Searching found that Times of Israel's liveblog reported that Channel 12 said Netanyahu and Mossad chief Roman Gofman sought an operation against Iran on the eve of the Oct 27 election. According to that report, an Israeli security operative's mistake tipped off the US, and Washington moved quickly to quash the operation. Middle East Eye, NewsBytes and Sunday Guardian Live also carried the report, apparently derived from Channel 12. Times of Israel adds that on Oct 25–26 Channels 12 and 13 had reported a confrontation between Netanyahu and IDF Chief of Staff Eyal Zamir over military action that could cause a flare-up with Iran. Those earlier reports described Zamir as the only security chief opposing it, which differs slightly from the claim's wording of 'other security chiefs objected'. I found no independent confirmation of the underlying events beyond Channel 12's anonymously sourced report. I found no Reuters, AFP, Bellingcat or EUvsDisinfo fact-check, and no official confirmation or denial.