Add link to security mailing list

Author: mudge

documentation/asciidoc/security/security.adoc

@@ -41,6 +41,8 @@ Raspberry Pi lists official security vulnerability disclosures on our website. F
 
 To report security issues on Raspberry Pi, email mailto:security@raspberrypi.com[security@raspberrypi.com]. For more information, see https://www.raspberrypi.com/security/#reporting-a-vulnerability[Reporting a vulnerability].
 
+To be notified by email of significant security vulnerabilities in Raspberry Pi products, subscribe using the https://www.raspberrypi.com/security/#subscribe[Be notified of security vulnerabilities] form on our security page.
+
 == Software Bill of Materials
 
 A Software Bill of Materials (SBOM) lists all components in a software application and includes metadata for each component, such as its name, version, supplier, license, and unique identifier. This information is provided in an open-standard, machine-readable format.

documentation/asciidoc/services/connect/security.adoc

@@ -68,6 +68,13 @@ In January 2025, penetration testing and security analysts at https://cure53.de[
 
 For more details on WebRTC security, see https://webrtc-security.github.io/[A Study of WebRTC Security].
 
+[[security-notifications]]
+=== Security notifications
+
+To be notified by email of significant security vulnerabilities in Raspberry Pi products, including Connect, subscribe using the https://www.raspberrypi.com/security/#subscribe[Be notified of security vulnerabilities] form on our security page.
+
+To report a vulnerability, see https://www.raspberrypi.com/security/#reporting-a-vulnerability[Reporting a vulnerability].
+
 [[sub-processors]]
 === Sub-processors