CVE-2026-22597 Overview
A Server-Side Request Forgery (SSRF) vulnerability has been identified in Ghost, a popular Node.js content management system. The vulnerability exists in Ghost's media inliner mechanism and allows authenticated staff users with a valid Admin API token to exfiltrate data from internal systems. This issue affects Ghost versions 5.38.0 through 5.130.5 and 6.0.0 through 6.10.3.
Critical Impact
Authenticated staff users can exploit the media inliner mechanism to perform SSRF attacks, potentially accessing internal network resources and exfiltrating sensitive data from systems not intended to be publicly accessible.
Affected Products
- Ghost CMS versions 5.38.0 through 5.130.5
- Ghost CMS versions 6.0.0 through 6.10.3
- Self-hosted Ghost installations with affected versions
Discovery Timeline
- 2026-01-10 - CVE-2026-22597 published to NVD
- 2026-01-13 - Last updated in NVD database
Technical Details for CVE-2026-22597
Vulnerability Analysis
This vulnerability is classified under CWE-918 (Server-Side Request Forgery), which occurs when a web application fetches a remote resource without properly validating the user-supplied URL. In Ghost CMS, the media inliner mechanism is designed to process and inline external media content. However, insufficient validation of URLs allows an attacker with staff-level access to craft malicious requests that target internal network resources.
The attack requires authentication with a valid Ghost Admin API token, limiting the attack surface to users who already have legitimate staff access to the Ghost installation. While this prerequisite reduces the risk significantly, it still poses a threat in scenarios involving compromised staff accounts or insider threats.
Root Cause
The root cause of this vulnerability lies in the insufficient URL validation within Ghost's media inliner functionality. When processing media URLs for inlining, the application fails to adequately verify that the target URL points to a legitimate external resource rather than internal network addresses or sensitive endpoints. This allows attackers to supply URLs targeting localhost, internal IP ranges, or cloud metadata services, causing the server to make unintended requests on behalf of the attacker.
Attack Vector
The attack is network-based and requires the attacker to possess valid staff-level credentials with access to the Ghost Admin API. The exploitation flow involves:
- An attacker with legitimate staff access authenticates to the Ghost Admin API
- The attacker crafts a request to the media inliner mechanism with a malicious URL targeting internal resources
- The Ghost server processes the request and fetches content from the specified internal URL
- The response data is returned to the attacker, allowing exfiltration of internal system information
The vulnerability could be used to probe internal network infrastructure, access cloud metadata services (such as AWS EC2 metadata at 169.254.169.254), or interact with internal services that are not exposed to the public internet.
Detection Methods for CVE-2026-22597
Indicators of Compromise
- Unusual outbound requests from the Ghost server to internal IP ranges (e.g., 10.x.x.x, 172.16.x.x, 192.168.x.x)
- Requests to cloud metadata endpoints such as 169.254.169.254
- Suspicious activity in Ghost Admin API logs involving the media inliner functionality
- Staff account activity patterns inconsistent with normal usage
Detection Strategies
- Monitor Ghost Admin API access logs for unusual media inliner requests
- Implement network monitoring to detect outbound requests to private IP address ranges from the Ghost server
- Deploy Web Application Firewall (WAF) rules to detect and block SSRF patterns
- Review authentication logs for staff accounts showing signs of compromise
Monitoring Recommendations
- Enable verbose logging for the Ghost Admin API to capture detailed request information
- Set up alerts for outbound connections from the Ghost server to internal network resources
- Monitor for failed or unusual authentication attempts on staff accounts
- Implement anomaly detection for Admin API usage patterns
How to Mitigate CVE-2026-22597
Immediate Actions Required
- Upgrade Ghost CMS to version 5.130.6 or 6.11.0 immediately
- Review Admin API access logs for any suspicious activity involving the media inliner
- Audit staff account permissions and revoke access for any compromised or unused accounts
- Implement network segmentation to limit the Ghost server's access to internal resources
Patch Information
The Ghost development team has released security patches addressing this vulnerability. Users should upgrade to the following fixed versions:
- For Ghost 5.x: Upgrade to version 5.130.6 or later
- For Ghost 6.x: Upgrade to version 6.11.0 or later
Patches are available through the official Ghost GitHub repository. For detailed commit information, see the security patch for version 5.x and the security patch for version 6.x. Additional details are available in the GitHub Security Advisory GHSA-vmc4-9828-r48r.
Workarounds
- Restrict network egress from the Ghost server to only necessary external destinations using firewall rules
- Implement a reverse proxy with URL filtering to block requests to internal IP ranges
- Review and minimize the number of staff accounts with Admin API access
- Consider deploying Ghost behind a WAF configured to detect SSRF patterns
# Example firewall configuration to block outbound requests to internal networks
# Block requests to private IP ranges from the Ghost server
iptables -A OUTPUT -d 10.0.0.0/8 -j DROP
iptables -A OUTPUT -d 172.16.0.0/12 -j DROP
iptables -A OUTPUT -d 192.168.0.0/16 -j DROP
iptables -A OUTPUT -d 169.254.169.254 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
