CVE-2026-49252: deepstream is vulnerable to prototype pollution

Severity: critical (CVSS 9.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-18 · updated 2026-10-26
Weakness: CWE-1321

Description

deepstream is a server that allows clients and backend services to sync data, send messages and make rpcs at scale. Versions prior to 10.0.5 are vulnerable to Prototype Pollution. Exploitation can lead to potential privilege escalation from any authenticated user with write permission to any record. This issue has been fixed in version 10.0.5.

Affected products

deepstreamIO deepstream.io: before 10.0.5

References

https://github.com/deepstreamIO/deepstream.io/commit/54b8e2958a98df444b5b5d9a66e22872afd84e44
https://github.com/deepstreamIO/deepstream.io/security/advisories/GHSA-9v98-6g37-x9g6

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