CVE-2026-41488
LOW3.1EPSS 0.03%langchain-openai: Image token counting SSRF protection can be bypassed via DNS rebinding
Published: 4/16/2026Modified: 5/20/2026
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.
Affected packages (2)
- PyPI/langchain-openaifrom 0, < 1.1.14
- PyPI/langchain-openaifrom 0, < 1.1.14
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | LOW3.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N |