Reject truncated nested modules and components - #2724
Merged
alexcrichton merged 1 commit intoOct 1, 2026
Merged
Conversation
This fixes an issue where `wasmparser` accepted malformed components whose declared size for a nested component or module was larger than the actual component or module. The bug is in `Parser` where when it returns `Payload::End` it only checks to see that we're at eof, not that we're at eof at the expected position.
pchickey
approved these changes
Oct 1, 2026
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
This fixes an issue where
wasmparseraccepted malformed components whose declared size for a nested component or module was larger than the actual component or module. The bug is inParserwhere when it returnsPayload::Endit only checks to see that we're at eof, not that we're at eof at the expected position.