CVE-2026-57757 Overview
CVE-2026-57757 is an unauthenticated Cross-Site Request Forgery (CSRF) vulnerability affecting the pCloud WP Backup WordPress plugin in versions up to and including 2.0.2. The flaw is tracked under CWE-352: Cross-Site Request Forgery and can be exploited over the network without prior authentication, though it requires user interaction such as clicking a crafted link. Successful exploitation lets an attacker force an authenticated administrator's browser to submit unintended requests to the plugin, altering backup configuration or triggering plugin actions.
Critical Impact
An attacker who tricks a logged-in WordPress administrator into visiting a malicious page can invoke pCloud WP Backup actions in the victim's session, potentially manipulating backup workflows tied to cloud storage.
Affected Products
- pCloud WP Backup WordPress plugin versions <= 2.0.2
- WordPress sites with the plugin installed and activated
- Administrator accounts that interact with the plugin's admin pages
Discovery Timeline
- 2026-07-02 - CVE-2026-57757 published to NVD
- 2026-07-02 - Last updated in NVD database
Technical Details for CVE-2026-57757
Vulnerability Analysis
The pCloud WP Backup plugin exposes state-changing actions through its administrative interface without adequately validating the origin of incoming requests. Because the plugin does not enforce anti-CSRF tokens (nonces) on the affected endpoints, any authenticated session can be leveraged by a remote attacker to submit forged requests. The advisory from Patchstack classifies the issue as unauthenticated, meaning the attacker themselves does not need credentials — they only need a victim with an active WordPress session to visit an attacker-controlled resource.
Root Cause
The root cause is missing or improper CSRF protection on privileged plugin endpoints. WordPress provides wp_nonce_field() and check_admin_referer() primitives specifically to prevent this class of attack, but the affected versions of pCloud WP Backup do not apply these checks to all sensitive request handlers. This maps directly to [CWE-352], where the server cannot distinguish a legitimate user-initiated request from one forged by a third-party site.
Attack Vector
An attacker crafts a malicious HTML page hosting an auto-submitting form or image tag targeting the vulnerable plugin endpoint on the victim's WordPress site. The attacker delivers the URL through phishing, forum posts, or malvertising. When a signed-in administrator loads the page, the browser attaches the WordPress session cookie and the forged request executes with the administrator's privileges. Impact skews toward confidentiality and integrity of backup data rather than direct code execution.
No verified public proof-of-concept code is available. See the Patchstack disclosure linked in the references for technical detail.
Detection Methods for CVE-2026-57757
Indicators of Compromise
- Unexpected changes to pCloud WP Backup plugin settings, credentials, or scheduled backup targets
- Administrator sessions submitting POST requests to plugin endpoints with Referer headers pointing to unrelated external domains
- New or modified backup jobs that administrators do not recognize
- Outbound connections from the WordPress host to pCloud endpoints that do not match documented backup windows
Detection Strategies
- Review WordPress web server access logs for requests to pCloud WP Backup admin-ajax or admin-post handlers with missing or invalid nonce parameters
- Correlate administrator authenticated sessions with cross-origin Referer headers to flag CSRF-style request patterns
- Alert on plugin configuration modifications occurring outside change-management windows
Monitoring Recommendations
- Enable WordPress audit logging to record plugin setting changes and the initiating user, IP, and referer
- Forward web server and WordPress audit logs to a centralized log platform for correlation and retention
- Track outbound API calls to pCloud from the WordPress host and baseline normal backup activity
How to Mitigate CVE-2026-57757
Immediate Actions Required
- Update pCloud WP Backup to a version later than 2.0.2 once the vendor publishes a fix
- Rotate any pCloud API credentials configured within the plugin, as their exposure cannot be ruled out following exploitation attempts
- Instruct administrators to log out of WordPress before browsing untrusted sites and to use separate browsers or profiles for administrative work
Patch Information
Refer to the Patchstack advisory for the current patched version and vendor guidance. Until a fix is confirmed, treat all installations at version 2.0.2 or earlier as vulnerable.
Workarounds
- Deactivate the pCloud WP Backup plugin until a patched release is available and validated
- Restrict access to the WordPress admin area with IP allowlisting or a VPN to shrink the pool of potential CSRF victims
- Deploy a web application firewall rule that blocks requests to plugin endpoints when the Referer header is missing or points outside the WordPress site
- Enforce SameSite=Lax or SameSite=Strict on WordPress authentication cookies to reduce cross-site request delivery
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
