CVE-2026-48759 Overview
CVE-2026-48759 is an Insecure Direct Object Reference (IDOR) vulnerability in TypeBot, an open-source chatbot builder. The flaw affects versions 3.15.2 and below and resides in the handleSaveThemeTemplate and handleDeleteThemeTemplate handlers. These handlers verify that the authenticated user belongs to the supplied workspaceId but fail to scope the underlying Prisma database queries by that same workspace. Any authenticated, non-guest user can modify or delete theme templates owned by other workspaces. The maintainers fixed the issue in version 3.16.0.
Critical Impact
Authenticated tenants can tamper with or destroy theme template assets across workspace boundaries, breaking multi-tenant isolation [CWE-639].
Affected Products
- TypeBot versions 3.15.2 and earlier
- handleSaveThemeTemplate server handler
- handleDeleteThemeTemplate server handler
Discovery Timeline
- 2026-06-17 - CVE-2026-48759 published to NVD
- 2026-06-17 - Last updated in NVD database
- TypeBot v3.16.0 - Fix released by the TypeBot maintainers
Technical Details for CVE-2026-48759
Vulnerability Analysis
The vulnerability is a classic IDOR pattern in a multi-tenant SaaS application. The handlers responsible for saving and deleting theme templates accept two attacker-controlled parameters: workspaceId and themeTemplateId. The code authorizes the caller against the supplied workspaceId, confirming the user is a non-guest member of that workspace. It then executes Prisma update and delete operations keyed only on themeTemplateId. Because the database WHERE clause omits the workspace identifier, the resolver acts on any template ID it receives, including those owned by other tenants. The check and the action are not bound to the same object.
Root Cause
The root cause is missing object-level authorization in the data layer. The application enforces workspace membership at the handler boundary but does not enforce a workspaceId predicate on the Prisma query that mutates the template. Authorization is decoupled from the resource being modified, satisfying the conditions described in [CWE-639: Authorization Bypass Through User-Controlled Key].
Attack Vector
Exploitation requires only a low-privileged authenticated account in any workspace on the same TypeBot instance. An attacker enumerates or harvests theme template IDs, which may be exposed through shared typebots, embedded assets, or observed network traffic. The attacker submits a request to the save or delete theme template endpoint with their own workspaceId and the victim workspace's themeTemplateId. The server validates membership in the attacker's workspace and then mutates the victim's template. Impact includes integrity loss (template tampering) and availability loss (template deletion). Confidentiality is not directly affected.
No public exploit code or proof-of-concept is referenced in the advisory. See the GitHub Security Advisory GHSA-qv4p-4mp3-pvpv for vendor details.
Detection Methods for CVE-2026-48759
Indicators of Compromise
- Unexpected modification or deletion of theme template records in the TypeBot database that cannot be attributed to a workspace owner.
- Application or proxy logs showing requests to theme template save or delete endpoints where the request's workspaceId does not match the workspace owning the targeted themeTemplateId.
- Audit-log gaps where theme templates change owners or content without a corresponding action by an authorized workspace member.
Detection Strategies
- Correlate themeTemplateId values in mutation requests against the workspace that owns them, and alert when the caller's session workspace differs.
- Hunt for one user account interacting with theme template IDs across multiple distinct workspaces in a short time window.
- Review TypeBot version strings in deployment manifests and container images to identify instances at or below 3.15.2.
Monitoring Recommendations
- Forward TypeBot application logs and reverse-proxy access logs to a central SIEM for query and retention.
- Enable database-level audit logging on the ThemeTemplate table to capture the identity, timestamp, and source IP of every UPDATE and DELETE.
- Track baseline rates of theme template mutations per workspace and alert on statistical anomalies.
How to Mitigate CVE-2026-48759
Immediate Actions Required
- Upgrade TypeBot to version 3.16.0 or later on every self-hosted instance.
- Inventory existing theme templates and validate ownership and content against a known-good backup.
- Rotate or revoke API tokens belonging to accounts that exhibited cross-workspace access patterns in historical logs.
Patch Information
The maintainers fixed the issue in TypeBot 3.16.0 by scoping the Prisma queries in handleSaveThemeTemplate and handleDeleteThemeTemplate to include workspaceId in the WHERE clause. Release notes are available in the GitHub Release v3.16.0.
Workarounds
- If immediate upgrade is not possible, restrict TypeBot instance access to trusted users only and disable open registration.
- Apply a reverse-proxy or WAF rule that rejects theme template save and delete requests where the requesting user's session workspace does not match the workspace owning the referenced template.
- Take a verified backup of the ThemeTemplate table to enable rapid restoration if tampering is detected.
# Upgrade self-hosted TypeBot to the patched release
git fetch --tags
git checkout v3.16.0
docker compose pull
docker compose up -d
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
