CVE-2026-57407 Overview
CVE-2026-57407 is a Server-Side Request Forgery (SSRF) vulnerability [CWE-918] in the WP Swings PDF Generator for WordPress plugin (pdf-generator-for-wp). The flaw affects all versions up to and including 1.6.2. Unauthenticated attackers can coerce the WordPress server into issuing arbitrary HTTP requests to attacker-chosen destinations. This exposes internal network services, cloud metadata endpoints, and other resources reachable from the hosting environment.
Critical Impact
Remote, unauthenticated attackers can abuse the PDF generation workflow to pivot into internal networks, enumerate services, and access sensitive metadata endpoints on cloud-hosted WordPress installations.
Affected Products
- WP Swings PDF Generator for WordPress plugin
- Plugin slug: pdf-generator-for-wp
- Versions from n/a through <= 1.6.2
Discovery Timeline
- 2026-07-13 - CVE-2026-57407 published to NVD
- 2026-07-13 - Last updated in NVD database
Technical Details for CVE-2026-57407
Vulnerability Analysis
The PDF Generator for WordPress plugin accepts user-controlled input that is passed to a server-side HTTP fetching routine without adequate validation of the destination. An attacker submits a crafted URL, and the plugin's PDF rendering backend retrieves that resource from the WordPress host. Because the request originates from the server, it bypasses network segmentation that would normally block external clients.
SSRF in a PDF generation context is especially useful to attackers. Rendering pipelines commonly follow embedded resources such as images, stylesheets, and remote HTML, expanding the attack surface beyond a single URL parameter. The exploit requires no authentication and no user interaction.
The CWE-918 classification confirms the root category: the server-side component fetches a remote resource using attacker-supplied input.
Root Cause
The plugin fails to validate or restrict the destination of outbound HTTP requests triggered during PDF generation. There is no allowlist of permitted hosts, no filtering of private IP ranges (RFC 1918, loopback, link-local 169.254.0.0/16), and no blocking of internal DNS names. Any URL supplied by an unauthenticated caller is fetched by the server.
Attack Vector
Exploitation occurs over the network against the WordPress site's public endpoints exposed by the plugin. An attacker sends a request that instructs the plugin to render a document referencing an internal URL, such as http://127.0.0.1:8080/admin, http://localhost/server-status, or a cloud metadata service at http://169.254.169.254/latest/meta-data/. The plugin fetches the target and may return the content, response codes, or timing information observable to the attacker.
No verified exploit code is publicly available. See the Patchstack advisory
referenced below for coordinated disclosure details.
Detection Methods for CVE-2026-57407
Indicators of Compromise
- Outbound HTTP requests from the WordPress host to internal IP ranges (127.0.0.0/8, 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16) originating from PHP worker processes.
- Access attempts against cloud metadata endpoints such as 169.254.169.254 from web server processes.
- Unusual PDF generation activity in pdf-generator-for-wp logs referencing external or internal URLs supplied by unauthenticated visitors.
Detection Strategies
- Inspect web server access logs for repeated calls to plugin endpoints under /wp-content/plugins/pdf-generator-for-wp/ or associated AJAX actions with URL parameters.
- Correlate egress network flows from the WordPress host with request timestamps to identify attacker-driven fetches.
- Deploy WAF rules that flag URL-valued parameters pointing to private address space or metadata IPs.
Monitoring Recommendations
- Enable outbound traffic logging on the WordPress host and alert on connections to link-local and RFC 1918 destinations.
- Restrict the WordPress process's ability to reach the instance metadata service using IMDSv2 with hop-limit enforcement.
- Track plugin version inventory across managed WordPress installations and alert on pdf-generator-for-wp versions <= 1.6.2.
How to Mitigate CVE-2026-57407
Immediate Actions Required
- Update the PDF Generator for WordPress plugin to a version later than 1.6.2 as soon as the vendor publishes a fix.
- If no patched version is available, deactivate and remove the pdf-generator-for-wp plugin until a fix ships.
- Block outbound traffic from the WordPress host to internal networks and cloud metadata endpoints at the network layer.
Patch Information
At the time of publication, refer to the Patchstack WordPress Vulnerability advisory for the latest fixed version and vendor guidance. Verify plugin integrity after upgrade by reviewing installed version metadata in the WordPress admin dashboard.
Workarounds
- Enforce egress filtering so the PHP-FPM or web server user cannot initiate connections to 127.0.0.0/8, 169.254.0.0/16, or private RFC 1918 ranges.
- Deploy a WAF signature that rejects requests to plugin endpoints containing URL parameters resolving to internal addresses.
- Require IMDSv2 with http-put-response-hop-limit set to 1 on AWS EC2 instances hosting WordPress to prevent metadata theft via SSRF.
# Example: block egress to metadata and internal ranges via iptables for the www-data user
iptables -A OUTPUT -m owner --uid-owner www-data -d 169.254.169.254 -j REJECT
iptables -A OUTPUT -m owner --uid-owner www-data -d 127.0.0.0/8 -j REJECT
iptables -A OUTPUT -m owner --uid-owner www-data -d 10.0.0.0/8 -j REJECT
iptables -A OUTPUT -m owner --uid-owner www-data -d 172.16.0.0/12 -j REJECT
iptables -A OUTPUT -m owner --uid-owner www-data -d 192.168.0.0/16 -j REJECT
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
