CVE-2026-48776: LangChain LangGraph SDK path traversal in URL construction

CVE-2026-48776 · Severity: medium · CVSS 4.2 · Published 2026-06-17

The LangGraph SDK, used for building agentic workflows, contains a vulnerability where it fails to properly clean user-provided identifiers before using them in web addresses. This could allow an attacker to manipulate the SDK into accessing, modifying, or deleting data they shouldn't have access to. The risk is highest for applications that pass raw user input directly to the SDK and rely on external security filters like firewalls that might be bypassed by this manipulation.

Technologies: langgraph (PyPI), langgraph-sdk (PyPI). Vendors: LangChain, PyPI.

Quick answers

Is CVE-2026-48776 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-48776 being exploited in the wild.
How severe is CVE-2026-48776?
Medium severity, with a CVSS score of 4.2, published 17 June 2026.
Which products and versions are affected?
LangChain LangGraph SDK <= 0.3.14; langgraph (PyPI) ECOSYSTEM:introduced=0,fixed=0.3.15; langgraph-sdk (PyPI) ECOSYSTEM:introduced=0,fixed=0.3.15.
Is there a fix for CVE-2026-48776?
Yes. langgraph (PyPI): upgrade to 0.3.15 or later; langgraph-sdk (PyPI): upgrade to 0.3.15 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-48776 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-48776?
Check whether you run LangChain LangGraph SDK, langgraph (PyPI) or langgraph-sdk (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • langgraph (PyPI): upgrade to 0.3.15 or later
    pip install "langgraph>=0.3.15"
  • langgraph-sdk (PyPI): upgrade to 0.3.15 or later
    pip install "langgraph-sdk>=0.3.15"

Technical details

The langgraph-sdk (Python) constructs HTTP request paths by interpolating caller-supplied identifier values into URL templates without proper path-segment encoding. An attacker providing identifiers containing special characters (e.g., '../' or other URL-significant characters) can cause the SDK to address a different resource or resource type than intended. This is classified as a path traversal (CWE-22) and incorrect authorization (CWE-863) issue. It is particularly exploitable when upstream security layers (WAFs, reverse proxies) perform authorization based on the intended URL prefix, which may differ from the final path delivered to the backend. The vulnerability is fixed in version 0.3.15 by applying proper path-segment encoding.

Affected products

  • LangChain langgraph-sdk < 0.3.15

Identifiers

  • CVE-2026-48776
  • GHSA-w39p-vh2g-g8g5
  • PYSEC-2026-2194
  • PYSEC-2026-2575

Timeline

  • 2026-05-22: disclosed: Initial publication to langchain-ai/langgraph
  • 2026-06-17: advisory: Published to NVD
  • 2026-06-25: patched: GitHub Advisory reviewed and updated with patch information

References

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