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AWS lambda: Add EventBridge custom event buses to recursive loop detection

Service: lambda · 2026-09-27 · Documentation low

File: lambda/latest/dg/invocation-recursion.md

Summary

Updates the list of services for which Lambda can detect recursive loops to include Amazon EventBridge Custom event buses, in both the detection statement and the caveat about undetected loops.

Security assessment

The edit expands documented recursion-detection coverage to EventBridge custom event buses, which mitigates runaway invocation/cost (resource-exhaustion-adjacent) but is a functional coverage update, not a fix for a specific vulnerability or incident.

Evidence

-Lambda currently detects recursive loops between your functions, Amazon SQS, Amazon S3, and Amazon SNS. Lambda also detects loops comprised only of Lambda functions, which might invoke each other synchronously or asynchronously. The following diagrams show some examples of loops that Lambda can detect:

Diff

diff --git a/lambda/latest/dg/invocation-recursion.md b/lambda/latest/dg/invocation-recursion.md
index c4d523b6a..1fd961a8e 100644
--- a//lambda/latest/dg/invocation-recursion.md
+++ b//lambda/latest/dg/invocation-recursion.md
@@ -60 +60 @@ Lambda can detect only recursive loops that include certain supported AWS servic
-Lambda currently detects recursive loops between your functions, Amazon SQS, Amazon S3, and Amazon SNS. Lambda also detects loops comprised only of Lambda functions, which might invoke each other synchronously or asynchronously. The following diagrams show some examples of loops that Lambda can detect:
+Lambda currently detects recursive loops between your functions, Amazon SQS, Amazon S3, Amazon SNS, and Amazon EventBridge Custom event buses. Lambda also detects loops comprised only of Lambda functions, which might invoke each other synchronously or asynchronously. The following diagrams show some examples of loops that Lambda can detect:
@@ -66 +66 @@ When another AWS service such as Amazon DynamoDB forms part of the loop, Lambda
-Because Lambda currently detects only recursive loops involving Amazon SQS, Amazon S3, and Amazon SNS, it's still possible that loops involving other AWS services can result in unintended usage of your Lambda functions.
+Because Lambda currently detects only recursive loops involving Amazon SQS, Amazon S3, Amazon SNS, and Amazon EventBridge Custom event buses, it's still possible that loops involving other AWS services can result in unintended usage of your Lambda functions.