CVE-2026-41488
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.
Does this matter?
Lower severity and a low EPSS score (0.16%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 3.1 LOWCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N
- EPSS
- 0.16% probability · 5th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-918
- Affected
- langchain/langchain-openai
- Source
- security-advisories@github.com
References
- https://github.com/langchain-ai/langchain/security/advisories/GHSA-r7w7-9xr2-qq2rMitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.