KEVWire

Security intelligence, with context.

Response snapshot Oct 29, 2026, 01:26 UTC

Back to the wire
Permalink
VulnerabilityCVE-2026-118667

LangGraph: Unencoded identifiers in LangGraph SDK v3 streaming can redirect authenticated GET requests

The LangGraph Python SDK v3 streaming client interpolates caller-supplied thread_id and assistant_id values into request paths without encoding them at four synchronous and asynchronous call sites.

At a glance

Exploited
Not known
Severity
4.3 Medium (CVSS 3.1)
Chance of exploitation
Not estimated
Sources
1 source

What to do

GitHub lists first patched versions: langgraph-sdk: 0.4.6; langgraph: 1.2.14. Confirm the affected range and upgrade guidance in the exact advisory.

Read GitHub-reviewed advisory GHSA-3fx2-cqw9-xr3c (opens a new tab)

What happened

Summary

The LangGraph Python SDK v3 streaming client interpolates caller-supplied thread_id and assistant_id values into request paths without encoding them at four synchronous and asynchronous call sites. Relative path segments can therefore redirect an authenticated GET request to another path on the same configured server.

Details

The affected get_tree and _fetch_state implementations build request paths from raw identifiers rather than passing each identifier through the SDK's existing _quote_path_param helper. HTTP path normalization can collapse values containing relative segments before dispatch while retaining the client's authentication headers.

Continue reading

langgraph-sdk versions 0.4.0 through 0.4.5 are affected. The v3 stream module is not present in the 0.3.x release line.

RemoteGraph v3 streaming in langgraph 1.2.3 and later is also affected when used with a vulnerable langgraph-sdk version. It passes config["configurable"]["thread_id"] into threads.stream(...), and its dependency range permits affected SDK versions.

Impact

An application is affected only if it passes attacker-controlled text as a streaming thread_id or assistant_id. In that configuration, an attacker may select another readable path on the configured server and cause the SDK to return that response to the application. Through thread_id, the attacker can also control the query string, for example by targeting /store/items?namespace=...&key=...

; assistant_id controls only the path. The affected requests are GET operations, so this issue does not provide a write primitive.

The LangGraph Platform is not exposed to this issue.

Remediation

Upgrade langgraph-sdk to version 0.4.6 or later. The fix encodes assistant_id in get_tree and thread_id in _fetch_state with _quote_path_param in both synchronous and asynchronous stream modules.

If you use RemoteGraph, also upgrade langgraph to version 1.2.14 or later, which requires langgraph-sdk>=0.4.6.

Affected package ranges reported by GitHub: langgraph-sdk: >= 0.4.0, < 0.4.6 langgraph: >= 1.2.3, < 1.2.14

Scores and how they were measured

CVSS base severity

4.3

Version 3.1As of

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

Not available

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    GitHub-reviewed advisory GHSA-3fx2-cqw9-xr3c (opens a new tab)

    The public advisory supplies the description, affected package/version ranges, and any listed CVSS metric. GitHub review is not local review.

    Published Checked

  2. Primary source

    GitHub public advisory API page (opens a new tab)

    The API page supplied GHSA-3fx2-cqw9-xr3c, its actual identifiers, source dates, and structured metrics.

    Published Date not suppliedChecked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 28). LangGraph: Unencoded identifiers in LangGraph SDK v3 streaming can redirect authenticated GET requests (CVE-2026-118667). https://kevwire.com/record/CVE-2026-118667

MLA

"LangGraph: Unencoded identifiers in LangGraph SDK v3 streaming can redirect authenticated GET requests (CVE-2026-118667)." KEVWire, 28 Oct. 2026, kevwire.com/record/CVE-2026-118667.

Chicago

KEVWire. "LangGraph: Unencoded identifiers in LangGraph SDK v3 streaming can redirect authenticated GET requests (CVE-2026-118667)." Last modified October 28, 2026. https://kevwire.com/record/CVE-2026-118667.

Evidence summary (plain text)

LangGraph: Unencoded identifiers in LangGraph SDK v3 streaming can redirect authenticated GET requests (Oct 28, 2026).
The LangGraph Python SDK v3 streaming client interpolates caller-supplied thread_id and assistant_id values into request paths without encoding them at four synchronous and asynchronous call sites. Relative path segments can therefore redirect an authenticated GET request to another path on the same configured server.

The affected get_tree and _fetch_state implementations build request paths from raw identifiers rather than passing each identifier through the SDK's existing _quote_path_param helper.
CVSS 4.3 (version 3.1; evidence as of Oct 28, 2026; https://github.com/advisories/GHSA-3fx2-cqw9-xr3c).
Sources:
GitHub-reviewed advisory GHSA-3fx2-cqw9-xr3c: https://github.com/advisories/GHSA-3fx2-cqw9-xr3c
GitHub public advisory API page: https://api.github.com/advisories?type=reviewed&per_page=100&sort=updated&direction=desc
Record ID: CVE-2026-118667.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 29, 2026, 00:55 UTC. Ingestion is not an independent editorial investigation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

Record JSON

Your account

Email alerts

Email alerts are coming as part of KEVWire Premium: join the waitlist. To follow your stack today, use its RSS feed, which honors your filters, or connect an AI agent through the API.

Suggest an improvement

Ideas, missing sources, corrections, and bugs are all welcome. No account needed. Suggestions are reviewed by a person before anything changes.

Record details

Record detail