Review reviewCritical

CVE-2026-49252

deepstreamIO deepstream.io

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.

CVSS
9.9
EPSS
0.47%
38.2% percentile
CISA KEV
Not listed
Published
2026.06.19
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.47%
Technical severityCVSS 9.9

Vulnerability overview

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 product and versions

Product
deepstreamIO deepstream.io
Affected versions
< 10.0.5
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that deepstreamIO deepstream.io and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L
CWE
CWE-1321