CVE-2026-30242 Overview
CVE-2026-30242 is a Server-Side Request Forgery (SSRF) vulnerability in Plane, an open-source project management tool. The vulnerability exists in the webhook URL validation logic within plane/app/serializers/webhook.py, which only checks for loopback addresses using ip.is_loopback. This insufficient validation allows attackers with workspace ADMIN role to create webhooks pointing to private and internal network addresses, including 10.x.x.x, 172.16.x.x, 192.168.x.x, and the AWS metadata endpoint 169.254.169.254. When webhook events fire, the server makes HTTP requests to these internal addresses and stores the full response, enabling SSRF with complete response read-back capabilities.
Critical Impact
Authenticated attackers with workspace ADMIN privileges can exploit this SSRF vulnerability to access internal network resources, cloud instance metadata, and sensitive services not intended to be externally accessible.
Affected Products
- Plane versions prior to 1.2.3
Discovery Timeline
- 2026-03-06 - CVE-2026-30242 published to NVD
- 2026-03-10 - Last updated in NVD database
Technical Details for CVE-2026-30242
Vulnerability Analysis
This SSRF vulnerability (CWE-918) stems from incomplete IP address validation in the webhook functionality. The webhook serializer in Plane only validates against loopback addresses (127.0.0.1, ::1), failing to account for RFC 1918 private network ranges and link-local addresses commonly used in cloud environments for metadata services.
When a user with workspace ADMIN privileges configures a webhook, they can specify a target URL pointing to internal network resources. The application then makes server-side HTTP requests to these URLs when webhook events are triggered, and critically, returns the full response content to the attacker. This creates a powerful SSRF primitive that enables reconnaissance and data exfiltration from internal infrastructure.
The vulnerability is particularly dangerous in cloud-hosted deployments where access to instance metadata services (such as 169.254.169.254 in AWS) can expose IAM credentials, API tokens, and other sensitive configuration data.
Root Cause
The root cause is insufficient URL validation in the plane/app/serializers/webhook.py file. The validation logic relies solely on Python's ip.is_loopback property to block internal addresses. This check fails to account for:
- Private IPv4 ranges: 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16
- Link-local addresses: 169.254.0.0/16 (including cloud metadata endpoints)
- IPv6 unique local addresses: fc00::/7
- Other non-routable address spaces
Attack Vector
An attacker with workspace ADMIN privileges in Plane can exploit this vulnerability through the following attack flow:
- Authenticate to Plane with workspace ADMIN credentials
- Create a new webhook configuration targeting an internal IP address (e.g., http://169.254.169.254/latest/meta-data/)
- Trigger a webhook event (such as creating or updating a project issue)
- The server makes an HTTP request to the attacker-specified internal URL
- The server stores and returns the full response content
- The attacker retrieves the response containing sensitive internal data
The vulnerability requires low-privilege authentication (workspace ADMIN role) but can result in access to highly sensitive internal resources and potential lateral movement within cloud or corporate networks.
Detection Methods for CVE-2026-30242
Indicators of Compromise
- Webhook configurations targeting private IP ranges (10.x.x.x, 172.16.x.x, 192.168.x.x)
- Webhook URLs pointing to cloud metadata endpoints (169.254.169.254)
- Unusual outbound HTTP connections from the Plane server to internal network addresses
- Webhook configurations with non-standard ports targeting internal services
Detection Strategies
- Monitor webhook configuration changes for URLs containing private IP addresses or metadata service endpoints
- Implement network-level monitoring for outbound connections from application servers to internal IP ranges
- Review webhook audit logs for suspicious URL patterns or high-frequency access attempts
- Deploy web application firewall rules to detect SSRF patterns in webhook URL parameters
Monitoring Recommendations
- Enable comprehensive logging for all webhook creation and modification events
- Configure alerting on network connections to RFC 1918 address ranges from the Plane application tier
- Monitor for access patterns consistent with metadata service enumeration (sequential requests to 169.254.169.254)
- Implement egress filtering and logging at the network perimeter
How to Mitigate CVE-2026-30242
Immediate Actions Required
- Upgrade Plane to version 1.2.3 or later immediately
- Audit existing webhook configurations for URLs targeting internal IP addresses
- Review webhook activity logs for evidence of exploitation
- Implement network-level egress controls to restrict Plane server access to internal resources
Patch Information
The vulnerability has been patched in Plane version 1.2.3. The patch enhances webhook URL validation to block all private and non-routable IP address ranges, not just loopback addresses. Organizations should upgrade to the patched version as soon as possible.
For detailed patch information, see the GitHub Release v1.2.3 and the GitHub Security Advisory GHSA-fpx8-73gf-7x73.
Workarounds
- Implement network-level egress filtering to prevent the Plane server from making HTTP connections to private IP ranges and cloud metadata endpoints
- Deploy a web application firewall with SSRF protection rules in front of the Plane application
- Restrict webhook creation permissions to trusted administrators only
- Use network segmentation to isolate the Plane application from sensitive internal services
# Example iptables rules to block SSRF to private networks from Plane server
# Block connections to private IPv4 ranges
iptables -A OUTPUT -d 10.0.0.0/8 -m owner --uid-owner www-data -j DROP
iptables -A OUTPUT -d 172.16.0.0/12 -m owner --uid-owner www-data -j DROP
iptables -A OUTPUT -d 192.168.0.0/16 -m owner --uid-owner www-data -j DROP
iptables -A OUTPUT -d 169.254.0.0/16 -m owner --uid-owner www-data -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
