CVE-2026-35219 in Budibase
Summary
by MITRE • 08/17/2026
Budibase is an open-source low-code platform. Prior to 3.41.3, automation steps in packages/server/src/automations/steps/outgoingWebhook.ts, packages/server/src/automations/steps/zapier.ts, packages/server/src/automations/steps/n8n.ts, packages/server/src/automations/steps/slack.ts, and packages/server/src/automations/steps/discord.ts use node-fetch on user-provided URLs without the BLACKLIST_IPS enforcement used by the REST integration, allowing an authenticated user to make server-side requests to cloud metadata and internal services. This issue is fixed in version 3.41.3.
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Analysis
by VulDB Data Team • 08/18/2026
The vulnerability identified in Budibase prior to version 3.41.3 represents a critical Server-Side Request Forgery (SSRF) flaw embedded within the platform's automation engine architecture. As an open-source low-code development environment, Budibase allows users to construct complex workflows that interact with external systems through various integration steps. The core technical deficiency lies in how specific outgoing webhook implementations handle URL validation and network access control. Specifically, the modules responsible for handling webhooks, Zapier integrations, n8n triggers, Slack notifications, and Discord messages utilize the node-fetch library to execute HTTP requests based on user-supplied URLs. Unlike other integration points within the application, such as the REST API handler which enforces a strict blacklist of internal IP ranges via BLACKLIST_IPS, these automation steps fail to apply equivalent network-level restrictions. This inconsistency creates an attack vector where authenticated users can bypass intended security boundaries by directing server-side requests toward sensitive destinations that should be inaccessible from the public-facing application layer.
From a technical perspective, this flaw enables an attacker who has obtained valid credentials for any user account on the Budibase instance to manipulate the automation engine into making arbitrary HTTP requests on behalf of the backend server. By crafting malicious workflow configurations or webhook payloads containing URLs pointing to cloud metadata services such as AWS EC2 Instance Metadata Service (IMDS), Azure Managed Identity endpoints, or Google Cloud metadata servers, an attacker can retrieve sensitive infrastructure data including access keys and security tokens. Furthermore, this capability extends beyond public cloud environments; it allows for the probing of internal network resources that are typically isolated from external internet traffic. This includes accessing local database services, administrative interfaces running on localhost ports, or other microservices within the deployment environment that rely on implicit trust in their network location rather than explicit authentication mechanisms.
The operational impact of this vulnerability is severe due to its potential for privilege escalation and data exfiltration. In cloud-native deployments where Budibase instances are hosted on virtual machines with attached instance roles, successful exploitation can lead to the compromise of long-lived credentials stored within metadata services. These credentials often possess broad permissions across other cloud resources such as S3 buckets, DynamoDB tables, or Kubernetes clusters. Additionally, in on-premises or hybrid environments, attackers could leverage this SSRF vector to pivot into internal networks, potentially accessing sensitive business logic APIs, database ports like MongoDB or PostgreSQL running on non-standard ports, or configuration management tools that are not exposed to the public internet but are reachable from within the application server's network namespace. This effectively neutralizes perimeter defenses and allows lateral movement across trusted segments of an infrastructure.
To mitigate this risk, organizations must immediately upgrade their Budibase installations to version 3.41.3 or later, where the developers have implemented consistent IP blacklisting logic across all outgoing webhook integration points. Until patching is feasible, administrators should consider implementing network-level controls such as egress filtering at the firewall or container runtime level to restrict outbound connections from the application server only to explicitly whitelisted domains and IPs. Additionally, deploying Web Application Firewalls with SSRF detection capabilities can provide an additional layer of defense by inspecting outgoing request patterns for indicators of metadata service access attempts. It is also advisable to review existing automation workflows for any configurations that permit dynamic URL input without rigorous validation or allowlist constraints, ensuring that the principle of least privilege is applied not just to user permissions but also to network egress policies governing server-side operations. This vulnerability aligns with CWE-918 which addresses Server-Side Request Forgery and maps to MITRE ATT&CK technique T1557 for Adversary-in-the-Middle scenarios involving credential theft via cloud metadata services, highlighting the importance of consistent security controls across all application modules regardless of their functional purpose.