FortiMail has a zero-day with no patch and active exploitation in the wild. Bird just borrowed $450M to pay shareholders while opening its mailboxes to AI agents. OpenAI is formally entering email marketing automation. And Microsoft shipped an emergency Exchange patch nobody saw coming. Moderate week, heavy security angle. Let's get into it.
CVE-2026-104286 scores a 9.8 on CVSS, requires no authentication, and attackers are already using it. It's a path-traversal/NULL-byte-neutralization flaw that lets unauthenticated attackers write arbitrary files to FortiMail appliances via crafted HTTP/HTTPS requests. CISA added it to the Known Exploited Vulnerabilities catalog on October 1, with an October 4 remediation deadline for federal agencies — a deadline that's already in the rearview mirror. Attackers are dropping web shells and malicious binaries on exposed boxes right now. Affects FortiMail 7.2.x through 8.0.1.
There's no patch. Only a workaround. If you run FortiMail as your mail security gateway — and a lot of enterprises do — detection and network isolation are doing the job a fix usually handles. That's not a comfortable place to operate from, and it won't get more comfortable until Fortinet ships something you can actually install. Isolate exposed appliances now.
Sources: CISA, SC World, SOCPrime
Sponsor this newsletter
Reach 228 people who build and run email.
This spot is open. One sponsor per issue, no competing ads — your logo, your words, and a link, right here in the middle of the read.
See rates and availability →$450M. That's the debt Bird (SparkPost's parent) just took on — a $400M term loan plus $50M revolver led by J.P. Morgan — and it's not going into product. It's going straight to a shareholder dividend. Headcount has shrunk from 1,000+ at peak to roughly 120, against $165M in 2025 EBITDA. In the same window, Bird launched "Agentic Harness": an MCP (Model Context Protocol) server and CLI that lets AI agents operate real mailboxes, either on a customer's own domain or on a shared domain called inbox.ai, plus a new Mailbox API pitched as "a real inbox your code owns."
Nobody's addressed the obvious question: how do shared-domain agent mailboxes survive the bulk-sender rules Gmail, Yahoo, and Microsoft now enforce at the SMTP level? When dozens or hundreds of agents share inbox.ai's reputation, one bad actor's mailbox becomes everyone's deliverability problem. Watch this space — "agent mailbox" is about to become a real abuse vector, not just a product category.
Source: emailexpert
GPT-6 Astra-powered agents, cloud compute, browser access, five specialist roles — and one of them is email marketing. That's OpenAI's "Dots" announcement from September 29, alongside accounting, legal, ticketing, and customer support dots. The email marketing dot is enterprise-pilot-only via direct sales, and OpenAI hasn't disclosed what it actually sends, what sending infrastructure it uses, or how consent and list management work. The general-purpose Dot is a separate track: it's rolling out to Pro/Business/Enterprise ChatGPT now (minus Pro users in the EEA, Switzerland, and UK), and it can act on your personal email, though it can't yet hold its own address.
A frontier AI lab formally entering email marketing automation is worth flagging even on fumes of detail. If you've been assuming AI-run send decisions were a 2027 problem, OpenAI just moved the timeline up. The consent and infrastructure questions don't go away because the pilot is enterprise-only — they're the first thing that surfaces the moment this goes wider.
Source: emailexpert
CVE-2026-96940 — CVSS 8.8 — lets an authenticated attacker read other users' mailboxes and attachments inside the same organization. Microsoft found it internally, says it hasn't seen active exploitation, and still pushed an out-of-band fix on October 2 for Exchange Server Subscription RTM, Exchange 2019 CU14/15, and Exchange 2016 CU23. The rollout itself was its own small mess: Microsoft silently patched Exchange Online days earlier with no accompanying documentation, catching admins off guard before the on-prem fix even shipped.
If you run on-prem Exchange, patch now — don't wait for the next Patch Tuesday cycle. An out-of-band release outside Microsoft's normal cadence is Microsoft telling you this one couldn't wait, whatever they're saying about exploitation risk.
Sources: Help Net Security, The Hacker News
That's the week. If something is wrong, reply and tell me — I read every response.
— John
This Week In Email — thisweekin.email
Subscribe to This Week in Email and get future issues delivered to your inbox.