CVE-2024-1455 Billion Laughs Attack leading to DoS in langchain-ai/langchain

What is CVE-2024-1455?

CVE-2024-1455 is a medium-severity denial of service vulnerability in langchain-ai/langchain, published on 26 Mar 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A vulnerability in the langchain-ai/langchain repository allows for a Billion Laughs Attack, a type of XML External Entity (XXE) exploitation. By nesting multiple layers of entities within an XML document, an attacker can cause the XML parser to consume excessive CPU and memory resources, leading to a denial of service (DoS).

Weakness: CWE-776

Which versions are affected by CVE-2024-1455?

3 open source packages ship an affected version, including langchain-core. It affects 1 product.

Products include Langchain Langchain.

How do I fix CVE-2024-1455?

Upgrade langchain-core to 0.1.35 or later.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2024-1455 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-1455 exists.

Other vulnerabilities in langchain-ai/langchain

• CVE-2023-39631 Langchain vulnerable to arbitrary code execution via the evaluate function in the numexpr library Critical 9.8
• CVE-2023-36281 langchain vulnerable to arbitrary code execution Critical 9.8
• CVE-2023-38860 LangChain vulnerable to arbitrary code execution Critical 9.8
• CVE-2023-38896 LangChain vulnerable to arbitrary code execution Critical 9.8
• CVE-2023-39659 LangChain vulnerable to arbitrary code execution Critical 9.8

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-q84m-rmw3-4382, PYSEC-2026-1519.