CVE-2025-71389

Severity CVSS v4.0:

CRITICAL

Type:

CWE-94 Code Injection

Publication date:

23/07/2026

Last modified:

30/07/2026

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 by updating the affected dependency.

Impact

Vector 4.0

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H CVSS v4.0 Severity and Metrics:

Base Score: 10.00 CRITICAL
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

Attack Vector (AV): Network
Attack Complexity (AC): Low
Attack Requirements (AT): None
Privileges Required (PR): None
User Interaction (UI): None
Confidentiality (VC): High
Integrity (VI): High
Availability (VA): High
Confidentiality (SC): High
Integrity (SI): High
Availability (SA): High

Base Score 4.0

10.00

Severity 4.0

CRITICAL

Vector 3.x

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 10.00 CRITICAL
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Changed
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x

10.00

Severity 3.x

CRITICAL

CVE-2025-71389

Description

Impact

References to Advisories, Solutions, and Tools