How severe is CVE-2026-49252?

CVE-2026-49252 has a CVSS 3.x base score of 9.9, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability low.

Is CVE-2026-49252 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-49252?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-49252 have an EU (EUVD) identifier?

Yes. CVE-2026-49252 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-37943.

When was CVE-2026-49252 published?

CVE-2026-49252 was published on 2026-06-18 and last updated on 2026-06-23.

CVE-2026-49252

CVE-2026-49252 is a critical-severity vulnerability with a CVSS 3.x base score of 9.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-1321.

Key facts

Severity: Critical (CVSS 3.x base score 9.9)
EPSS exploit prediction: 0% (19th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-37943
Weakness: CWE-1321
Published: 2026-06-18
Last modified: 2026-06-23

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.

Frequently asked questions

What is CVE-2026-49252?: 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.
How severe is CVE-2026-49252?: CVE-2026-49252 has a CVSS 3.x base score of 9.9, rated critical severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability low.
Is CVE-2026-49252 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-49252?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-49252 have an EU (EUVD) identifier?: Yes. CVE-2026-49252 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-37943.
When was CVE-2026-49252 published?: CVE-2026-49252 was published on 2026-06-18 and last updated on 2026-06-23.

References

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CVE-2020-12079 — Critical (CVSS 10.0): Beaker before 0.8.9 allows a sandbox escape, enabling system access and code execution. This occurs because Electron…

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