Lambda functions on a deprecated or soon-deprecated runtime — updates blocked from Aug 31, 2027

AWSDeprecations & retirementsTeam planSeverity: highaws.lambda

Lambda functions on runtimes that are deprecated or deprecating within ~6 months; Lambda blocks function create on July 29, 2027 and function update on August 31, 2027

What LeftSize checks

Find Lambda functions on a runtime that is deprecated, or will be deprecated within ~6 months (verified 2026-10-27).

Why it matters

Missed retirement and end-of-support dates turn into forced upgrades, outages or extended support charges at a moment you did not choose.

What you get in the GitHub issue

LeftSize runs this check from a scheduled GitHub Action with a read-only identity in your AWS account and opens one issue per scope, updated on every scan. The issue includes:

  • The affected resources, grouped per subscription, resource group or account and region
  • Background on why it was flagged and when it is a false positive
  • Cost and operational impact of fixing it
  • Step-by-step remediation with safety checks
  • Ready-to-run fix scripts (CLI, PowerShell or Terraform where available)
  • Alternative approaches and their trade-offs
  • Snooze, ignore or report a finding with a comment on the issue
Install LeftSizeIncluded in the Team and Business plans.

Official references