Detect Prototype Pollution in @deepstream/server (CVE-2026-49252) in Sumo Logic CSE
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
Sumo Detection Query
_sourceCategory=*node* OR _sourceCategory=*deepstream* OR _sourceName=*deepstream*
| where _raw matches "*deepstream*" or _raw matches "*@deepstream/server*"
| parse regex field=_raw "(?<proto_keyword>__proto__|constructor|Object\.prototype)" nodrop
| if(isNull(proto_keyword), "clean", proto_keyword) as proto_keyword
| count by _sourceHost, _sourceName, proto_keyword, _messagetime
| where proto_keyword != "clean"
| order by _messagetime descSumo Logic query targeting deepstream server log sources and identifying prototype pollution keyword patterns in application log messages.
Data Sources
False Positives & Tuning
- Verbose Node.js logging frameworks that serialize full objects including prototype metadata
- npm audit or snyk scan results ingested into Sumo Logic containing vulnerability descriptions
- Development or staging deepstream instances where prototype keywords appear in test traffic
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
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