AWS AWSCloudFormation documentation change
Summary
Added clarification about regex support limitations in CloudFormation intrinsic functions
Security assessment
Explicitly states regex limitations to prevent misconfigurations, helping users avoid potential template validation errors. While not fixing a specific security issue, it adds preventive security documentation by clarifying proper usage patterns.
Diff
diff --git a/AWSCloudFormation/latest/UserGuide/cfn-regexes.md b/AWSCloudFormation/latest/UserGuide/cfn-regexes.md index 9dc4d2833..c1dff8f20 100644 --- a//AWSCloudFormation/latest/UserGuide/cfn-regexes.md +++ b//AWSCloudFormation/latest/UserGuide/cfn-regexes.md @@ -34,0 +35,4 @@ If you write your CloudFormation template in YAML syntax, you must surround the +###### Note + +Regular expressions in CloudFormation are only supported for validation purposes in specific contexts like `AllowedPattern`. They are not supported as pattern matching operations in CloudFormation intrinsic functions, such as `Fn::Equals`, which perform exact string comparison only, not pattern matching. +