CVE-2025-27097
📋 TL;DR
GraphQL Mesh has a variable caching vulnerability where initial GraphQL query variables persist across subsequent requests with different variables until cache eviction. This allows token reuse across different user sessions, potentially causing authentication bypass. Affects GraphQL Mesh deployments using root-level or single-source transforms.
💻 Affected Systems
- GraphQL Mesh
📦 What is this software?
Graphql Mesh by The Guild
Graphql Mesh by The Guild
Graphql Mesh by The Guild
Graphql Mesh by The Guild
⚠️ Risk & Real-World Impact
Worst Case
Authentication tokens from one user session could be reused for another user's requests, leading to unauthorized data access or privilege escalation.
Likely Case
Intermittent authentication issues where users might access data belonging to other users during the cache retention period.
If Mitigated
Limited impact with proper authentication validation and short cache durations, though some session mixing may still occur.
🎯 Exploit Status
Requires understanding of GraphQL Mesh transforms and ability to send multiple queries with different variables. Exploitation depends on specific application authentication implementation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.99.0 and later
Vendor Advisory: https://github.com/ardatan/graphql-mesh/security/advisories/GHSA-rr4x-crhf-8886
Restart Required: No
Instructions:
1. Update GraphQL Mesh to version 0.99.0 or later using npm/yarn/pnpm. 2. Run 'npm update @graphql-mesh/runtime' or equivalent for your package manager. 3. No service restart required as this is a library update.
🔧 Temporary Workarounds
Disable root-level transforms
allTemporarily disable root-level or single-source transforms if not essential for functionality
Modify GraphQL Mesh configuration to remove or comment out transform sections
Reduce cache size
allConfigure smaller LRU cache size to accelerate DocumentNode eviction
Set 'lruCacheMax' to lower value in GraphQL Mesh configuration
🧯 If You Can't Patch
- Implement additional authentication validation at application layer to verify tokens per request
- Monitor for unusual authentication patterns and implement rate limiting on GraphQL endpoints
🔍 How to Verify
Check if Vulnerable:
Check GraphQL Mesh version and verify if root-level transforms are configured. Vulnerable if version <0.99.0 AND using transforms.Check Version:
npm list @graphql-mesh/runtime or check package.json versionVerify Fix Applied:
Verify GraphQL Mesh version is 0.99.0 or later. Test with multiple queries containing different variables to ensure proper variable handling.📡 Detection & Monitoring
Log Indicators:
- Multiple GraphQL requests with different variables returning same authentication results
- Unexpected user context switches in application logs
Network Indicators:
- Repeated GraphQL queries with varying variable payloads
- Unusual authentication token reuse patterns
SIEM Query:
graphql.request AND (variable.token != null) | stats count by user, session_id | where count > threshold