A Browser, a Plugin, a Package, a Login Screen
This week's roundup keeps circling back to the same theme: attackers aren't breaking new ground, they're finding fresh angles into things people already trust — a browser extension, a build plugin, an npm package, a login page. Here's what mattered.
Cisco ISE Maximum-Severity Authentication Bypass
Cisco disclosed CVE-2026-76460, a CVSS 10.0 flaw in Identity Services Engine that lets an unauthenticated remote attacker bypass authentication entirely. The root cause is "insufficient authentication control on an API endpoint," meaning a specially crafted request against that endpoint is enough to gain unauthorized device access — no credentials required. Given ISE's role as a network access control chokepoint, unpatched instances should be treated as an emergency, not a routine patch cycle item.
An AI Agent Chained Two Bugs Into an OpenAI Breach
In one of the more striking items this week, researchers used Anthropic's Claude Opus 5 to autonomously chain two separate vulnerabilities — an SSO misconfiguration and a libheif remote code execution bug (CVE-2026-32882) in Discourse — into unauthorized access to internal OpenAI repositories and employee ChatGPT accounts. The flaw was patched roughly 14 hours after disclosure. Separately, AI Security firm AIR Security identified "Plugin4Shell," a zero-click RCE that bypasses SHA-pinning protections across four widely used AI coding agents: Claude Code, OpenAI Codex, GitHub Copilot, and Google Gemini CLI.
ClickFix Keeps Scaling
ClickFix — the social-engineering technique that tricks users into pasting and running malicious commands via a fake CAPTCHA or fix-it prompt — had a busy week:
- Brevo/Cloudflare supply chain attack: A compromised Cloudflare API key let attackers inject malicious code into over 100,000 websites in a five-hour window, displaying fake CAPTCHA prompts to visitors of sites including Trezor, CoinTracking, and BitBox.
- Google Docs variant: Huntress disclosed a campaign abusing Google Docs sidebars to deliver the AMOS infostealer on macOS and PowerShell loaders on Windows.
- Crypto-focused campaign: A separate operation abused the Google Visualization API for command-and-control, using obfuscated JavaScript to drain at least 49 BTC addresses worth more than $10,000.
Browser Hijacking Targets Banking Sessions
The KREMLIN banking malware family installs malicious extensions into Chrome and Edge to steal credentials and session tokens, using multi-stage JavaScript loaders and custom C++ installers to primarily target Brazilian banking users.
Why This Matters
Two threads worth pulling on from this week: first, AI coding and agentic tools are now both attack surface (Plugin4Shell) and attack tooling (the Claude-chained OpenAI breach) at the same time — that dual role is going to keep showing up. Second, ClickFix has fully matured from a niche technique into a scalable distribution channel, now riding on compromised supply chain infrastructure (Cloudflare API keys) rather than just phishing emails. Patch Cisco ISE now if you run it, and treat any "paste this to fix it" prompt as hostile by default.