CVE-2026-26013: LangChain is a framework for building agents and LLM-powered applications. Prior to 1.2.11, the ChatOpenAI.get_num_token

CVE-2026-26013 is a Server-Side Request Forgery (SSRF) vulnerability in LangChain, a framework for building agents and LLM-powered applications. Prior to version 1.2.11, the ChatOpenAI.get_num_tokens_from_messages() method fetches arbitrary image_url values without validation when computing token counts for vision-enabled models, allowing attackers to trigger SSRF attacks through malicious image URLs in user input.