LangGraph SDK has unsafe URL path constructionGHSA-w39p-vh2g-g8g5
MEDIUMGHSA-w39p-vh2g-g8g5 is a medium-severity (CVSS 4.2) Path Traversal vulnerability in langgraph-sdk. A fix is available for langgraph-sdk — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-w39p-vh2g-g8g5.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
langgraph-sdkReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
langgraph-sdk constructs HTTP request paths for resource operations by interpolating caller-supplied identifier values into URL templates. 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.
There have no evidence of this behavior being triggered in the wild. This change is intended to reduce the surface available when caller-supplied identifier values originate from untrusted sources.
Affected users / systems
You may be affected if you:
- use
langgraph-sdk(Python) to address resources by identifier, and - pass identifier values into SDK methods that originate from end-user input, untrusted third-party callers, or any source that does not validate identifier format before the SDK call.
Applications that validate identifier values (for example, by parsing them as UUIDs and rejecting anything that does not parse) before passing them to SDK methods are not affected. Validated UUIDs round-trip through the SDK request path unchanged.
Impact
- Potential unintended access, modification, or deletion of resources via SDK methods called for a different resource type, when caller-supplied identifier values are not validated.
- In deployments with prefix-based authorization at an upstream layer, the authorization decision and the final delivered request path may diverge.
- Confidentiality: disclosure of resource content beyond the authorization scope of the calling user.
- Integrity: modification or deletion of resources beyond the authorization scope of the calling user.
Patches / mitigation
The SDK now applies path-segment encoding to identifier values before they are interpolated into request URL templates. After this change, identifier values that contain characters with special meaning in URL paths are transmitted as encoded byte sequences and routed to the resource the SDK method's call site indicates.
Compatibility
Identifier values that match the standard UUID format, or any other format that contains only characters safe to transmit unencoded in URL path segments, round-trip through the SDK request path unchanged. Applications that already validate identifier inputs see no behavioral change.
Operational guidance
- Validate identifier values (typically as UUIDs) at the boundary where untrusted input enters the application, before passing them to SDK methods.
- For deployments relying on URL-prefix-based authorization upstream of LangGraph, prefer authorization at the LangGraph server layer or on parsed-and-validated request paths rather than on raw URL prefixes.
LangSmith / hosted deployments note
This issue affects the SDK that runs in caller applications. The LangGraph server runtime, including LangSmith-hosted deployments, receives ordinary HTTP requests on documented routes and is not itself affected by this issue. Applications that consume LangSmith-hosted services via langgraph-sdk and pass untrusted identifier values to SDK methods should upgrade.
First reported by: pucagit (CyStack).
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | langgraph-sdk | all versions | 0.3.15pip install --upgrade 'langgraph-sdk==0.3.15' |
Affected Products
langgraph-sdklangchainDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for langgraph-sdk, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update langgraph-sdk to 0.3.15 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-w39p-vh2g-g8g5 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
A flaw was found in the LangGraph Python SDK. Unsafe URL path construction allows unauthorized resource access when untrusted end-user input is passed directly into SDK identifier parameters. An attacker can craft identifier values containing path traversal sequences to access resources outside the intended scope.
Validate all identifier values (e.g., by parsing as UUIDs and rejecting non-conforming input) at the application boundary before passing them to langgraph-sdk methods. Avoid forwarding untrusted end-user input directly into SDK identifier parameters. For deployments using URL-prefix-based authorization upstream of LangGraph servers, enforce authorization at the LangGraph server layer or on parsed-and-validated request paths rather than on raw URL prefixes. Updating langgraph-sdk to version 0.3.15 or later applies percent-encoding to path segments and fully resolves this issue.Source: Red Hat security advisory for GHSA-w39p-vh2g-g8g5 (CC BY 4.0)
Frequently Asked Questions
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