calcom cal.diy up to 5.9.8 React Server Components Request deserialization

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.0$0-$5k4.47

Summaryinfo

A vulnerability was found in calcom cal.diy up to 5.9.8 and classified as critical. This impacts an unknown function of the component React Server Components Request Handler. Such manipulation leads to deserialization. This vulnerability is referenced as CVE-2025-71389. It is possible to launch the attack remotely. No exploit is available.

Detailsinfo

A vulnerability was found in calcom cal.diy up to 5.9.8 and classified as critical. Affected by this issue is an unknown code of the component React Server Components Request Handler. The manipulation with an unknown input leads to a deserialization vulnerability. Using CWE to declare the problem leads to CWE-502. The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is handled as CVE-2025-71389 since 07/16/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are neither technical details nor an exploit publicly available.

Upgrading to version 5.9.9 eliminates this vulnerability.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.3
VulDB Meta Temp Score: 7.0

VulDB Base Score: 7.3
VulDB Temp Score: 7.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Deserialization
CWE: CWE-502 / CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: cal.diy 5.9.9

Timelineinfo

07/16/2026 CVE reserved
07/23/2026 +7 days Advisory disclosed
07/23/2026 +0 days VulDB entry created
07/23/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2025-71389 (🔒)
GCVE (CVE): GCVE-0-2025-71389
GCVE (VulDB): GCVE-100-382820

Entryinfo

Created: 07/23/2026 23:53
Changes: 07/23/2026 23:53 (54)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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