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AWS lambda documentation change

Service: lambda · 2026-03-22 · Documentation medium

File: lambda/latest/dg/configuration-envvars.md

Summary

Added documentation for AWS_LAMBDA_METADATA_API and AWS_LAMBDA_METADATA_TOKEN environment variables

Security assessment

Documents security-related metadata endpoint authentication tokens used for runtime environment authentication. While security-related, this describes existing functionality rather than addressing a vulnerability.

Diff

diff --git a/lambda/latest/dg/configuration-envvars.md b/lambda/latest/dg/configuration-envvars.md
index 3c2c291e4..c15529967 100644
--- a//lambda/latest/dg/configuration-envvars.md
+++ b//lambda/latest/dg/configuration-envvars.md
@@ -330,0 +331,4 @@ Lambda [runtimes](./lambda-runtimes.html) set several environment variables duri
+  * `AWS_LAMBDA_METADATA_API` – The [metadata endpoint](./configuration-metadata-endpoint.html) server address in the format `{ipv4_address}:{port}` (for example, `169.254.100.1:9001`).
+
+  * `AWS_LAMBDA_METADATA_TOKEN` – A unique authentication token for the current execution environment used to authenticate requests to the [metadata endpoint](./configuration-metadata-endpoint.html). Lambda generates this token automatically at initialization.
+