Calcom vulnerabilities

CVE-2026-109143 Medium · 5.4 CWE-266 Oct 13, 2026

calcom cal.com/cal.diy Credentials delete credentials.delete privileges management

A vulnerability was determined in calcom cal.com and cal.diy up to 6.2.0. This vulnerability affects the function credentials.delete of the file /api/trpc/credentials/delete of the component Credentials Handler. This manipulation of the argument teamId causes improper privilege management. The attack can be initiated remotely. The exploit has been publicly disclosed and may be utilized. The vendor was contacted early about this disclosure but did not respond in any way.

CVE-2026-57858 High · 8.9 CWE-79 Aug 12, 2026

Cal.com Cal.diy 6.2.0 Stored XSS via BookingPageTagManager Analytics Tracking ID

Cal.com Cal.diy versions 2.1.1 through 6.2.0 contain a stored cross-site scripting vulnerability in the BookingPageTagManager component that allows authenticated event owners to inject arbitrary JavaScript by supplying a malicious analytics tracking ID without sanitization. Attackers can close the inline script string literal with a crafted payload that executes in the browser of every visitor to the affected public booking page, enabling session cookie theft, forged authenticated requests, and wormable propagation by chaining with CSRF-able endpoints to persist payloads on additional events.

CVE-2025-71389 Critical · 10.0 CWE-94 Jul 23, 2026

Cal.com before 5.9.9 Remote Code Execution via RSC

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.

CVE-2024-58355 High · 8.9 CWE-80 Jul 23, 2026

Cal.com through 4.7.15 Cross-Site Scripting via booking questions

Cal.com (calcom/cal.diy) versions through 4.7.15 contain a stored cross-site scripting vulnerability. The single booking view (e.g., https://app.cal.com/booking/<id>) renders booking-question field labels via React's dangerouslySetInnerHTML without sanitizing or escaping user input. An attacker who can create an event type with a malicious booking-question label can inject arbitrary HTML/JavaScript that executes when a victim opens the crafted booking URL. The issue is fixed in v4.7.16.

CVE-2024-58354 Critical · 9.9 CWE-77 Jul 23, 2026

cal.com Repository Takeover via pull_request_target Workflow

cal.com (calcom repository, later renamed cal.diy) is affected by a repository takeover vulnerability in its GitHub Actions workflows. The workflow pr.yml uses the pull_request_target trigger with the repository's default write permissions and passes them down to check-types.yml. check-types.yml then performs a 'dangerous' checkout of the attacker-submitted pull request code (via the dangerous-git-checkout action) and subsequently executes it (through yarn install and package.json scripts). An attacker can open a pull request whose code runs arbitrary commands with the repository's write-scoped GITHUB_TOKEN, allowing them to push commits, merge or mutate pull requests, add or delete comments, and delete or force-push branches, thereby compromising the repository. The main branch is affected; no patched version is available.

CVE-2024-58353 High · 8.9 CWE-80 Jul 23, 2026

Cal.com through 4.7.15 Cross-Site Scripting via booking questions

Cal.com (repository calcom/cal.diy) in versions <= 4.7.15 is vulnerable to cross-site scripting (XSS) on the publicly accessible single booking view (e.g., /booking/<id>). Booking question (form field) labels are rendered via React's dangerouslySetInnerHTML without proper input sanitization or CSP, so an attacker who can create an event type with a malicious booking question label can inject arbitrary HTML/JavaScript that executes when a victim visits the booking view URL. Self-hosted instances with open registration are particularly at risk. The issue is fixed in version 4.7.16.

CVE-2026-16624 Critical · 9.6 CWE-639 Jul 22, 2026

CVE-2026-16624

Cal.com OSS ships lacks authorization on webhook teamId creation, allowing any authenticated user to create a webhook on any team via unvalidated teamId injection, then steal booking data, including fields like organizer/attendee emails and custom responses, and conditionally video-call passwords, by triggering webhook delivery.

CVE-2026-63768 Medium · 4.3 CWE-601 Jul 20, 2026

cal.diy 6.2.0 Conferencing OAuth Callback Open Redirect via Unsigned State

cal.diy through 6.2.0 contains an open redirect vulnerability in the conferencing OAuth callback endpoint that allows attackers to redirect users to arbitrary URLs by crafting malicious state parameters. Attackers can exploit the unsigned state parameter and onErrorReturnTo field to silently redirect visitors from the trusted domain to attacker-controlled URLs for phishing attacks.

CVE-2026-9349 Medium · 5.3 CWE-200 May 24, 2026

calcom cal.diy Generic React API bookings-single-view.getServerSideProps.tsx getServerSideProps information disclosure

A vulnerability was determined in calcom cal.diy up to 4.9.4. Affected by this issue is the function getServerSideProps of the file apps/web/modules/bookings/views/bookings-single-view.getServerSideProps.tsx of the component Generic React API. This manipulation of the argument cancelledBy/rescheduledBy causes information disclosure. The attack can be initiated remotely. The exploit has been publicly disclosed and may be utilized. The vendor was contacted early about this disclosure but did not respond in any way.

CVE-2026-9304 Medium · 5.0 CWE-918 May 23, 2026

calcom cal.diy Logo API route.ts validateUrlForSSRF server-side request forgery

A security flaw has been discovered in calcom cal.diy up to 4.9.4. The affected element is the function validateUrlForSSRF of the file apps/web/app/api/logo/route.ts of the component Logo API. The manipulation results in server-side request forgery. It is possible to launch the attack remotely. Attacks of this nature are highly complex. The exploitability is described as difficult. The exploit has been released to the public and may be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.

CVE-2026-9303 Medium · 4.3 CWE-352 May 23, 2026

calcom cal.diy cross-site request forgery

A vulnerability was identified in calcom cal.diy up to 4.9.4. Impacted is an unknown function. The manipulation leads to cross-site request forgery. It is possible to initiate the attack remotely. The exploit is publicly available and might be used. The vendor was contacted early about this disclosure but did not respond in any way.

CVE-2026-23478 Critical · 9.8 CWE-602 Jan 13, 2026

Cal.com has an Authentication Bypass via Unvalidated Email in Custom JWT Callback

Cal.com is open-source scheduling software. From 3.1.6 to before 6.0.7, there is a vulnerability in a custom NextAuth JWT callback that allows attackers to gain full authenticated access to any user's account by supplying a target email address via session.update(). This vulnerability is fixed in 6.0.7.

CVE-2025-66489 Critical · 9.8 CWE-303 Dec 3, 2025

Cal.com Authentication Bypass via bad TOTP + password checks

Cal.com is open-source scheduling software. Prior to 5.9.8, A flaw in the login credentials provider allows an attacker to bypass password verification when a TOTP code is provided, potentially gaining unauthorized access to user accounts. This issue exists due to problematic conditional logic in the authentication flow. This vulnerability is fixed in 5.9.8.