CVE-2026-41488

Description

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.

PUBLISHED Reserved 2026-04-20 | Published 2026-04-24 | Updated 2026-04-27 | Assigner GitHub_M

Problem types

CWE-918: Server-Side Request Forgery (SSRF)

Product status

References

github.com/...gchain/security/advisories/GHSA-r7w7-9xr2-qq2r

cve.org (CVE-2026-41488)

nvd.nist.gov (CVE-2026-41488)

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