CVE-2026-27745: SPIP interface_traduction_objets RCE Flaw

CVE-2026-27745 Overview

The SPIP interface_traduction_objets plugin versions prior to 2.2.2 contain an authenticated remote code execution vulnerability in the translation interface workflow. The plugin incorporates untrusted request data into a hidden form field that is rendered without SPIP output filtering. Because fields prefixed with an underscore bypass protection mechanisms and the hidden content is rendered with filtering disabled, an authenticated attacker with editor-level privileges can inject crafted content that is evaluated through SPIP's template processing chain, resulting in execution of code in the context of the web server.

Critical Impact

Authenticated attackers with editor-level access can achieve remote code execution on the underlying web server, potentially leading to complete system compromise, data exfiltration, and lateral movement within the network infrastructure.

Affected Products

• SPIP interface_traduction_objets plugin versions prior to 2.2.2
• SPIP CMS installations with the vulnerable translation interface plugin enabled
• Web servers hosting SPIP deployments with editor-level user accounts

Discovery Timeline

• 2026-02-25 - CVE-2026-27745 published to NVD
• 2026-02-26 - Last updated in NVD database

Technical Details for CVE-2026-27745

Vulnerability Analysis

This vulnerability is classified as CWE-94 (Improper Control of Generation of Code), commonly known as Code Injection. The flaw exists in the translation interface workflow of the interface_traduction_objets plugin for SPIP CMS.

The core issue stems from improper handling of user-controlled input within the translation interface. When processing translation requests, the plugin takes untrusted request data and incorporates it into a hidden form field. This hidden field is subsequently rendered without applying SPIP's standard output filtering mechanisms.

A critical design flaw amplifies this vulnerability: fields prefixed with an underscore character bypass SPIP's built-in protection mechanisms. Combined with the disabled filtering on hidden content, this creates a pathway for attackers to inject malicious payloads that are processed through SPIP's template engine.

The attack requires authentication with at least editor-level privileges, which provides a minimal barrier to exploitation. Once the injected content passes through SPIP's template processing chain, arbitrary code execution occurs within the context of the web server process, inheriting all permissions associated with that service account.

Root Cause

The root cause is insufficient input validation and output encoding in the translation interface workflow. The plugin fails to properly sanitize user-supplied data before incorporating it into form fields, and the combination of underscore-prefixed field bypass and disabled filtering creates an exploitable code injection vector. The template processing engine evaluates the injected content as executable code rather than treating it as static data.

Attack Vector

The attack vector is network-based and requires authentication with editor-level privileges. An attacker would authenticate to the SPIP CMS, navigate to the translation interface provided by the vulnerable plugin, and craft a malicious request containing injectable payloads in parameters that are incorporated into underscore-prefixed hidden form fields.

The exploitation chain follows this sequence: the attacker submits crafted content through the translation interface, the plugin incorporates this content into a hidden form field without proper sanitization, the underscore prefix bypasses protection mechanisms, the hidden content is rendered with filtering disabled, and finally SPIP's template engine evaluates the malicious payload as code. The resulting code execution occurs with the privileges of the web server process.

For detailed technical analysis and proof-of-concept information, see the Chocapikk Vulnerability Report and the Vulncheck Advisory on SPIP RCE.

Detection Methods for CVE-2026-27745

Indicators of Compromise

• Unusual HTTP POST requests to translation interface endpoints containing template syntax or code patterns
• Web server logs showing unexpected child process spawning following requests to the interface_traduction_objets plugin paths
• Anomalous file system activity or new file creation in web-accessible directories by the web server process
• Network connections originating from the web server process to external hosts

Detection Strategies

• Monitor web application logs for requests containing SPIP template syntax injection patterns in translation interface parameters
• Implement web application firewall (WAF) rules to detect code injection attempts targeting SPIP template processing
• Analyze authentication logs for editor-level accounts exhibiting suspicious access patterns to translation interface endpoints
• Deploy endpoint detection and response (EDR) solutions to identify anomalous process execution chains from web server processes

Monitoring Recommendations

• Enable verbose logging on SPIP CMS installations to capture detailed request parameters for forensic analysis
• Configure intrusion detection systems to alert on code execution indicators from web server processes
• Implement file integrity monitoring on SPIP installation directories to detect unauthorized modifications
• Review access logs for the interface_traduction_objets plugin endpoints regularly

How to Mitigate CVE-2026-27745

Immediate Actions Required

• Upgrade the interface_traduction_objets plugin to version 2.2.2 or later immediately
• Audit editor-level accounts and revoke unnecessary privileges until patching is complete
• Review recent web server logs for signs of exploitation attempts
• Consider temporarily disabling the translation interface plugin if immediate patching is not feasible

Patch Information

The vulnerability has been addressed in interface_traduction_objets version 2.2.2. The security fix is available in commit db3417b7811774f04c3ff191ca1737fe660ef0be in the SPIP plugin repository.

Organizations should apply the patch by updating to the latest plugin version through the SPIP plugin management interface or by manually updating from the official repository. For additional context, refer to the SPIP Security Update Announcement and the SPIP Commit Changes Log.

Workarounds

• Disable the interface_traduction_objets plugin entirely if translation functionality is not critical to operations
• Implement strict network access controls to limit exposure of the SPIP administrative interface
• Restrict editor-level account privileges and enforce multi-factor authentication for all CMS accounts
• Deploy a web application firewall with rules specifically targeting code injection attempts in SPIP parameters

# Configuration example - Disable the vulnerable plugin
# Navigate to SPIP administration and disable the plugin
# Or remove from the plugins directory:
mv /var/www/spip/plugins/interface_traduction_objets /var/www/spip/plugins-disabled/

# Verify plugin is disabled
ls -la /var/www/spip/plugins/ | grep interface_traduction