CVE-2026-41488 LOW

CVE-2026-41488: angchain-openai: Image token counting SSRF protection can be bypassed via DNS rebinding

Vendor Langchain-Ai
Product langchain-openai
Weakness CWE-918 · SSRF
Published April 24, 2026
Last update April 27, 2026
View on NVD All CVEs

CVSS base score

3.1/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction Required
Confidentiality Low
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

April 24, 2026 CVE published
April 27, 2026 Record updated