MEDIUM CVSS 4.2
Published: 2026-06-17

CVE-2026-48776

langchain langgraph-sdk Security Advisory (CVE-2026-48776)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-48776 impacting langchain langgraph-sdk. Evaluated with CVSS Base Score of 4.2 (MEDIUM).

Original NVD Description

Source: NIST NVD
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.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
High (AC:H)
Depends on race conditions or environment
Privileges Required
Low (PR:L)
Standard user access required
User Interaction
None (UI:N)
Zero human interaction required
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
Low (C:L)
Partial information leakage
Integrity
Low (I:L)
Partial data modification possible
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product langchain / langgraph-sdk
Affected Versions *
Weakness Enumeration CWE-22

Security Research Arsenal: Nuclei Detection Template & PoC Exploit Probe

High-Intent Research Tool

Ready-to-use security scanner signatures, active verification probe skeletons, and remediation playbooks for CVE-2026-48776 impacting langchain langgraph-sdk.

⚡ Nuclei Detection Template (YAML) cve-2026-48776.yaml
id: cve-2026-48776

info:
  name: langchain langgraph-sdk - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-48776 affecting langchain langgraph-sdk.
    Evaluation: LangGraph Python SDK is used to connect to running LangGraph API servers, manage assistants, threads and stream runs from Python applications. Version...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-48776
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N
    cvss-score: 4.2
    cve-id: CVE-2026-48776
    cwe-id: CWE-22
  tags: cve,cve-2026-48776,langchain,langgraph-sdk,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "langgraph-sdk"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-48776.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-48776
# Target: langchain langgraph-sdk | CVSS: 4.2 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-48776 (langchain langgraph-sdk)...")
    headers = {
        "User-Agent": "CyberVault-Audit-Scanner/2.0",
        "Accept": "*/*"
    }
    try:
        r = requests.get(f"{target_url.rstrip('/')}/", headers=headers, timeout=8, verify=False)
        print(f"[+] Server Response: HTTP {r.status_code} | Server Banner: {r.headers.get('Server', 'Unknown')}")
        if r.status_code < 500:
            print(f"[!] Target reachable. Verify version against langchain langgraph-sdk scope (*).")
        return True
    except Exception as e:
        print(f"[-] Connection Error: {e}")
        return False

if __name__ == '__main__':
    url = sys.argv[1] if len(sys.argv) > 1 else "http://localhost:8080"
    verify_vulnerability(url)
🛡️ Quick Patch & Remediation Script (Bash) patch_cve-2026-48776.sh
# Recommended Remediation & Patching Commands for CVE-2026-48776
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install langgraph-sdk 2>/dev/null || \
sudo dnf upgrade langgraph-sdk 2>/dev/null || \
sudo yum update langgraph-sdk

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i langgraph-sdk 2>/dev/null || rpm -qa | grep -i langgraph-sdk

# 3. Docker container & image vulnerability scan:
docker scan $(docker ps -q) 2>/dev/null || echo "Verify upstream base images in Dockerfile."

🛡️ Remediation & Security Action

  • Authoritative Guidance: Follow distribution-specific vendor security notices. Advisory status and package patches vary by distribution release.
  • Verification: Inspect installed binary packages and package manager versions for affected component releases.
  • Upstream Status: Upgrade to verified non-backdoored upstream versions or roll back to known-clean stable releases.
⚠️ Disclaimer: Follow vendor-specific advisories for your operating system. CyberVault does not fabricate unsupported remediation scripts.

🔗 Verified Technical References

Authorities
  • No records filed in this category.
Distributions
  • No records filed in this category.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-48776 in langchain langgraph-sdk?

Review vendor-specific security notices and update langchain langgraph-sdk packages to the latest patched release immediately. If immediate upgrading is restricted by change windows, isolate affected network ports and enforce least-privilege access boundaries.

Is there an active exploit or public PoC for CVE-2026-48776?

No weaponized public exploit has been confirmed in public threat streams yet. Continuous surveillance is active across GitHub and security feeds.

What is the CVSS 3.1 severity rating and impact for CVE-2026-48776?

CVE-2026-48776 is classified with a CVSS 3.1 Base Score of 4.2 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
4.2
MEDIUM SEVERITY
CVE ID CVE-2026-48776
Weakness CWE-22
Vendor langchain
Product langgraph-sdk
Published 2026-06-17
Vector CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N