Hi @Zac_Clifton, welcome to the community!
Thank you for the report. This is indeed a bug in the analyzer: S6957 can crash when React dependencies use pnpm catalog: version specifiers instead of a semver range.
This is already tracked in this ticket. The fix is completed and will be included in the next version of SonarQube Community Build 26.4.0.
Sorry for the trouble, and thanks for helping us improve the tool.