CVE-2025-71389
Cal.com before 5.9.9 Remote Code Execution via RSC
- State
- Published
- Severity
- 10.0 Critical
- Published
- Jul 23, 2026
- Updated
- Jul 28, 2026
- Reserved
- Jul 16, 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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 10.0 Critical | 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 | VulnCheck |
| 3.1 | 10.0 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H | VulnCheck |
Weaknesses
- CWE-94 Improper Control of Generation of Code ('Code Injection')
Affected Products
| Product | Versions |
|---|---|
cal.diycalcom |
|
References
- GitHub Security Advisory (GHSA-qjx2-5xqp-cpf4)vendor-advisory
- Patch (PR #25592)issue-trackingpatch
- Upstream Next.js advisory (CVE-2025-55182)related
- VulnCheck Advisory: Cal.com before 5.9.9 Remote Code Execution via RSCthird-party-advisory
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