Detect Prototype Pollution in @deepstream/server (CVE-2026-49252) in CrowdStrike LogScale
CVE-2026-49252 is a critical prototype pollution vulnerability (CVSS 9.9) in @deepstream/server versions prior to 10.0.5. An attacker can manipulate JavaScript object prototypes via crafted deepstream messages, potentially leading to remote code execution, privilege escalation, or denial of service within the Node.js server process.
MITRE ATT&CK
LogScale Detection Query
DeviceProcessEvents
| filter timestamp > now() - 24h
| filter (
ImageFileName contains "node" or
CommandLine contains "deepstream"
)
| filter (
CommandLine contains "__proto__" or
CommandLine contains "constructor" or
CommandLine contains "prototype"
)
| select timestamp, DeviceName, UserName, ImageFileName, CommandLine, ParentImageFileName, ParentCommandLine, SHA256HashData
| sort timestamp desc
| limit 1000CrowdStrike Falcon CQL query for Node.js/deepstream process events where command lines include prototype pollution indicators, helping identify active exploitation or post-exploitation activity.
Data Sources
Required Tables
False Positives & Tuning
- Legitimate Node.js scripts invoked by administrators that reference prototype keywords for debugging
- CrowdStrike RTR scripts running Node.js diagnostics on deepstream hosts
- Automated update or deployment scripts for deepstream that include version or config strings mentioning prototype
Other platforms for CVE-2026-49252
Testing Methodology
Validate this detection against 3 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1Deepstream Prototype Pollution via Crafted Client Message
Expected signal: Node.js application logs should show receipt of a record set message with __proto__ key; process monitoring may show unexpected property on Object.prototype after message processing
- Test 2deepstream Server Version Enumeration
Expected signal: Process execution event for node reading package.json; stdout output containing version string below 10.0.5 confirms vulnerability
- Test 3Prototype Pollution Object Property Verification
Expected signal: Node.js process execution with inline script; stdout output 'YES - VULNERABLE' confirms Object.prototype susceptibility
Unlock Pro Content
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