{"id":"PYSEC-2026-76","details":"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.","aliases":["CVE-2026-41488","GHSA-r7w7-9xr2-qq2r"],"modified":"2026-05-20T09:19:04.187253Z","published":"2026-04-24T21:16:19.637Z","references":[{"type":"ADVISORY","url":"https://github.com/langchain-ai/langchain/security/advisories/GHSA-r7w7-9xr2-qq2r"}],"affected":[{"package":{"name":"langchain-openai","ecosystem":"PyPI","purl":"pkg:pypi/langchain-openai"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.1.14"}]}],"versions":["0.0.1","0.0.1rc0","0.0.1rc1","0.0.2","0.0.2.post1","0.0.3","0.0.4","0.0.5","0.0.6","0.0.7","0.0.8","0.0.8rc1","0.1.0","0.1.1","0.1.10","0.1.11","0.1.12","0.1.13","0.1.14","0.1.15","0.1.16","0.1.17","0.1.19","0.1.2","0.1.20","0.1.21","0.1.21rc1","0.1.21rc2","0.1.22","0.1.23","0.1.24","0.1.25","0.1.3","0.1.3rc1","0.1.4","0.1.5","0.1.6","0.1.7","0.1.8","0.1.8rc1","0.1.9","0.2.0","0.2.0.dev0","0.2.0.dev1","0.2.0.dev2","0.2.1","0.2.10","0.2.11","0.2.12","0.2.13","0.2.14","0.2.2","0.2.3","0.2.4","0.2.5","0.2.6","0.2.7","0.2.8","0.2.9","0.3.0","0.3.1","0.3.10","0.3.11","0.3.12","0.3.13","0.3.14","0.3.15","0.3.16","0.3.17","0.3.18","0.3.19","0.3.2","0.3.20","0.3.21","0.3.22","0.3.23","0.3.24","0.3.25","0.3.26","0.3.27","0.3.28","0.3.29","0.3.3","0.3.30","0.3.31","0.3.32","0.3.33","0.3.34","0.3.35","0.3.4","0.3.4rc1","0.3.5","0.3.6","0.3.7","0.3.8","0.3.9","0.3.9rc1","0.4.0.dev0","1.0.0","1.0.0a1","1.0.0a2","1.0.0a3","1.0.0a4","1.0.1","1.0.2","1.0.3","1.1.0","1.1.1","1.1.10","1.1.11","1.1.12","1.1.13","1.1.2","1.1.3","1.1.4","1.1.5","1.1.6","1.1.7","1.1.8","1.1.9"],"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/langchain-openai/PYSEC-2026-76.yaml"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N"}]}