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CRITICAL

CVE-2025-71389

CVSS v3

10

CRITICAL

EPSS Score

1.4 %

exploit probability, as of 2026-09-25

CISA KEV

No

known exploited

Exploitation

—

SSVC status

Description

Cal.com (calcom/cal.diy) before 5.9.9 is vulnerable to unauthenticated remote code execution because it bundles a version of Next.js whose React Server Components (RSC) request handling deserializes attacker-controlled input. A remote attacker can send a crafted RSC request to the server and cause arbitrary code to be executed during server-side processing, without authentication or user interaction. The flaw derives from the upstream Next.js vulnerability CVE-2025-55182 and is resolved in 5.9.9

Technical details

Published
2026-07-23
Last Modified
2026-07-24

Frequently asked questions

What is CVE-2025-71389?

Cal.com (calcom/cal.diy) before 5.9.9 is vulnerable to unauthenticated remote code execution because it bundles a version of Next.js whose React Server Components (RSC) request handling deserializes attacker-controlled input. A remote attacker can send a crafted RSC request to the server and cause arbitrary code to be executed during server-side processing, without authentication or user interaction. The flaw derives from the upstream Next.js vulnerability CVE-2025-55182 and is resolved in 5.9.9

Is CVE-2025-71389 actively exploited?

Active exploitation of CVE-2025-71389 has not been confirmed. Its EPSS score was 1.4% on 2026-09-25, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2025-71389?

CVE-2025-71389 has a CVSS v3 base score of 10 (CRITICAL severity).

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