CVE-2025-71389

Cal.com before 5.9.9 Remote Code Execution via RSC

Published Jul 23, 2026 CVSS 4.0 · 10 Critical EPSS 1.4% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Cal
Cal cal.com
CPEs cpe:2.3:a:cal:cal.com:*:*:*:*:*:*:*:*
Vendors & Products Cal
Cal cal.com
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Calcom
Calcom cal.diy
Vendors & Products Calcom
Calcom cal.diy
Type Values Removed Values Added
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.
Title Cal.com before 5.9.9 Remote Code Execution via RSC
Weaknesses CWE-94
References
Metrics cvssV3_1

{'score': 10, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H'}

cvssV4_0

{'score': 10, '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Jul 28, 2026, 1:48 AM
Reserved
Jul 16, 2026, 12:14 PM
Status
Deferred
Published
Jul 23, 2026, 10:16 PM
Modified
Sep 29, 2026, 2:10 PM