diff --git a/SECURITY.md b/SECURITY.md
index a96843895..18c921723 100644
--- a/SECURITY.md
+++ b/SECURITY.md
@@ -4,6 +4,52 @@ Sensitive security-related questions, comments, and reports should be sent to
 the [gvisor-security mailing list][gvisor-security-list]. You should receive a
 prompt response, typically within 48 hours.
 
+## Security issue taxonomy
+
+We distinguish the following type of issues, listed from most to least severe:
+
+-   Issues that go **beyond the sandbox boundary**:
+    -   **Container escapes**: Issues that allow arbitrary code to run on the
+        host machine.
+        -   gVisor's purpose is to prevent these.
+    -   **Data exfiltration** from the host: Issues that allow reading arbitrary
+        files or file metadata from the host (other than those intended to be
+        visible to the sandbox).
+    -   **Sandbox-to-sandbox lateral movement**: Issues that allow arbitrary
+        code execution in a different sandbox on the same host.
+    -   **Denial-of-service attacks** that affect **the host kernel** (i.e.
+        trigger a host kernel panic).
+    -   **Denial-of-service attacks** that affect **other sandboxes on the same
+        host**.
+        -   This excludes things like causing CPU starvation when a sandbox is
+            running without resource constraints.
+-   Issues that **remain confined to a single sandbox**:
+    -   **Denial-of-service attacks** that affect a single sandbox and are
+        **triggerable remotely** (e.g. by sending a specially-crafted network
+        packet).
+    -   **Privilege escalation within the sandbox** (e.g. being able to do what
+        in-sandbox `root` would be able to do from an in-sandbox non-`root`
+        user).
+    -   **Denial-of-service attacks** that affect a single sandbox and are
+        **triggerable from user code** running in that sandbox.
+    -   **Data integrity issues** relative to Linux behavior.
+        -   gVisor aims to be bug-for-bug compatible with Linux. While most
+            compatibility issues are not security issues, it is conceivable that
+            some compatibility issues may manifest as persistent data
+            corruption; for example, differences in I/O syscall implementations
+            may cause a database program to end up storing invalid data.
+
+While all of the above are security issues, we generally only assign CVEs for
+issues that go beyond the sandbox boundary. Since gVisor is a container security
+platform, its main security focus is on preventing a user workload from "getting
+out of the box", relative to issues that remain within the proverbial box.
+Therefore, security issues that remain contained to a single sandbox are not
+considered critical and are not given CVE numbers by default. If you would still
+like to get a CVE number issued, you may report it to
+[BugHunter](https://g.co/vulnz).
+
+## Security list access
+
 Policies for security list access, vulnerability embargo, and vulnerability
 disclosure are outlined in the [governance policy](GOVERNANCE.md).