CVE-2026-40087

A flaw was found in LangChain. A missing validation of f-string prompt templates in some classes, specifically in DictPromptTemplate and ImagePromptTemplate, can cause the evaluation of attribute access or indexing expressions during template formatting. Also, f-string validation based on parsed...

CVE-2026-40087

LangChain is a framework for building agents and LLM-powered applications. Prior to 0.3.84 and 1.2.28, LangChain's f-string prompt-template validation was incomplete in two respects. First, some prompt template classes accepted f-string templates and formatted them without enforcing the same...