If you have heard of the Brevo supply-chain attack, you can skip to the next paragraph. If not, here’s a quick primer:
https://www.securityweek.com/brevo-supply-chain-attack-injects-malware-into-100000-websites/
Jacob Krell with Suzu Labs says the incident is another example of how compromising a trusted vendor, embedded script or API key can quickly extend the impact across its downstream customers. He also points to the growing attack surface created by long-lived credentials used by AI agents and stored in MCP configurations.
Jacob Krell, Sr. Director: Secure AI Solutions & Cybersecurity (https://www.linkedin.com/in/jacob-krell)
“The same supply chain pattern keeps repeating in the news at a seemingly increasing rate. Compromise one trusted vendor, one embedded script, or one API key, and you inherit every customer downstream. Agentic AI work is widening that surface because every agent ships with long-lived tokens for Cloudflare, Amazon Web Services (AWS), email, ticketing, and source control, usually parked in Model Context Protocol (MCP) configs on hosts we still do not inventory like developer laptops.
“Brevo is the latest example of how fast that fans out. Attackers used a hardcoded Cloudflare API key with full account permissions to deploy a Worker that rewrote JavaScript at the content delivery network (CDN) edge for the email and marketing platform’s sites and for the forms and SDK loader files customers embed on their own properties. Origin files never changed, so integrity checks stayed green while the Worker stripped Content-Security-Policy headers on the way out. For about five and a half hours on September 14, selected visitors got ClickFix lures dressed as Cloudflare verification, and logged-in WordPress administrators could receive a silent plugin that survived after Brevo tore the Worker down.
“I’m seeing attackers skip the application and go straight for the credential that can rewrite what customers already trust. I would map every API key an agent can reach with the same rigor you map third-party JavaScript on your homepage, because Brevo just showed you do not need to breach the vendor’s app to own the blast radius.”
Supply chain attacks are preventable. The discipline to not trust those around you and check everything that you rely on is a big reason why they don’t work. All that is needed to exercise that discipline.
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This entry was posted on September 19, 2026 at 6:50 pm and is filed under Commentary with tags Hacked. You can follow any responses to this entry through the RSS 2.0 feed.
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The bigger lesson from the Brevo supply-chain attack
If you have heard of the Brevo supply-chain attack, you can skip to the next paragraph. If not, here’s a quick primer:
https://www.securityweek.com/brevo-supply-chain-attack-injects-malware-into-100000-websites/
Jacob Krell with Suzu Labs says the incident is another example of how compromising a trusted vendor, embedded script or API key can quickly extend the impact across its downstream customers. He also points to the growing attack surface created by long-lived credentials used by AI agents and stored in MCP configurations.
Jacob Krell, Sr. Director: Secure AI Solutions & Cybersecurity (https://www.linkedin.com/in/jacob-krell)
“The same supply chain pattern keeps repeating in the news at a seemingly increasing rate. Compromise one trusted vendor, one embedded script, or one API key, and you inherit every customer downstream. Agentic AI work is widening that surface because every agent ships with long-lived tokens for Cloudflare, Amazon Web Services (AWS), email, ticketing, and source control, usually parked in Model Context Protocol (MCP) configs on hosts we still do not inventory like developer laptops.
“Brevo is the latest example of how fast that fans out. Attackers used a hardcoded Cloudflare API key with full account permissions to deploy a Worker that rewrote JavaScript at the content delivery network (CDN) edge for the email and marketing platform’s sites and for the forms and SDK loader files customers embed on their own properties. Origin files never changed, so integrity checks stayed green while the Worker stripped Content-Security-Policy headers on the way out. For about five and a half hours on September 14, selected visitors got ClickFix lures dressed as Cloudflare verification, and logged-in WordPress administrators could receive a silent plugin that survived after Brevo tore the Worker down.
“I’m seeing attackers skip the application and go straight for the credential that can rewrite what customers already trust. I would map every API key an agent can reach with the same rigor you map third-party JavaScript on your homepage, because Brevo just showed you do not need to breach the vendor’s app to own the blast radius.”
Supply chain attacks are preventable. The discipline to not trust those around you and check everything that you rely on is a big reason why they don’t work. All that is needed to exercise that discipline.
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This entry was posted on September 19, 2026 at 6:50 pm and is filed under Commentary with tags Hacked. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.