Severity by source
AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N
Primary rating from GitHub Advisory · only source for this CVE.
CVSS VectorGitHub Advisory
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N
Lifecycle Timeline
4Blast Radius
ecosystem impact- 5 pypi packages depend on langchain-openai (5 direct, 0 indirect)
Ecosystem-wide dependent count for version 1.1.14.
DescriptionGitHub Advisory
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.
Analysis
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.
Same weakness CWE-918 – Server-Side Request Forgery (SSRF)
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-25635