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.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact High

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact High

Subsequent System Integrity Impact High

Subsequent System Availability Impact High

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Changed

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
calcom cal.diy unaffected
Version Status Constraints
0 affected < 5.9.9
5.9.9 unaffected —

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Project Subscriptions

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Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/advisories/GHSA-9qr9-h5gf-34mp cve-icon
https://github.com/calcom/cal.diy/pull/25592 cve-icon
https://github.com/calcom/cal.diy/security/advisories/GHSA-qjx2-5xqp-cpf4 cve-icon
https://www.vulncheck.com/advisories/cal-com-before-remote-code-execution-via-rsc cve-icon
History

Thu, 23 Jul 2026 21:45:00 +0000

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'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-07-23T21:16:44.870Z

Reserved: 2026-07-16T12:14:41.769Z

Link: CVE-2025-71389

cve-icon Vulnrichment

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cve-icon NVD

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cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses