Zyxel GS1900 Patch Bypass: The June Fix Failed, Run the .3 Build

Binarly discovered an exploit in the wild that bypasses Zyxel's June 2026 fix for CVE-2026-7273 affecting GS1900 switches running firmware builds ending in .2, allowing unauthenticated adjacent-network remote code execution by abusing a POST parameter parsing flaw; Zyxel released .3 builds for ten affected models and recommends updating to those builds, restricting web management to a management network, and reviewing access logs.