CVE-2026-41488: Langchain Langchain-Openai

Low severity, CVSS 3.1. EPSS: 0.2% chance of exploitation in the next 30 days.

LangChain is a framework for building agents and LLM-powered applications. Prior to 1.1.14, langchain-openai's _url_to_size() helper (used by get_num_tokens_from_messages for image token counting) validated URLs for SSRF protection and then fetched them in a separate network operation with independent DNS resolution. This left a TOCTOU / DNS rebinding window: an attacker-controlled hostname could resolve to a public IP during validation and then to a private/localhost IP during the actual fetch.

Affected products

• Langchain Langchain-Openai: before 1.1.14 (fixed in 1.1.14)

Published 2026-04-24. Last modified 2026-06-17.