CVE-2026-41488 — angchain-openai: Image token counting SSRF protection can be bypassed via DNS rebinding
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 im…
Published: 2026-04-24 · CVSS: 3.1 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7