CVE-2026-7262 Overview
CVE-2026-7262 is a NULL pointer dereference vulnerability [CWE-476] in the PHP SOAP server component. The flaw exists in the typemap decoding process, where the implementation checks the wrong variable when a value element is missing. This logic error causes the SOAP server to dereference a NULL pointer, triggering a segmentation fault. A remote unauthenticated attacker can send a crafted SOAP request to crash the PHP SOAP server process, producing a denial of service condition. The issue affects PHP versions 8.2.x before 8.2.31, 8.3.x before 8.3.31, 8.4.x before 8.4.21, and 8.5.x before 8.5.6.
Critical Impact
Remote unauthenticated attackers can crash PHP SOAP server processes that use a configured typemap, resulting in service disruption.
Affected Products
- PHP 8.2.x before 8.2.31
- PHP 8.3.x before 8.3.31
- PHP 8.4.x before 8.4.21 and PHP 8.5.x before 8.5.6
Discovery Timeline
- 2026-05-10 - CVE-2026-7262 published to NVD
- 2026-05-12 - Last updated in NVD database
Technical Details for CVE-2026-7262
Vulnerability Analysis
The vulnerability resides in the PHP SOAP server's typemap decoding logic. When a SOAP server is configured with a typemap, the server invokes custom decoding callbacks to translate incoming XML elements into PHP values. The decoding routine must validate that the expected value element is present before dereferencing it. The defective code inspects the wrong variable during this check, so a missing value element bypasses the guard and a NULL pointer reaches the dereference operation. The result is a segmentation fault that terminates the PHP worker process handling the request.
Root Cause
The root cause is an incorrect variable reference in the conditional that guards against missing value elements during typemap decoding. The check inspects an unrelated pointer instead of the one about to be dereferenced. This is a classic [CWE-476] NULL pointer dereference. Additional technical context is available in the PHP Security Advisory GHSA-hmxp-6pc4-f3vv.
Attack Vector
Exploitation requires network access to a PHP SOAP server that has a typemap configured. The attacker sends a crafted SOAP request that omits the value element expected by the typemap decoder. No authentication or user interaction is required. The PHP process handling the request crashes, and repeated requests can sustain a denial of service against the SOAP endpoint. The flaw does not provide code execution, information disclosure, or integrity impact.
No verified public proof-of-concept exploit code is available at this time. Refer to the vendor advisory for technical details on the affected code path.
Detection Methods for CVE-2026-7262
Indicators of Compromise
- Repeated segmentation faults or SIGSEGV signals logged for PHP-FPM, Apache mod_php, or CLI SOAP server worker processes.
- Abnormal restart cycles or core dumps generated by PHP processes serving SOAP endpoints with typemap configurations.
- Inbound SOAP requests to typemap-enabled endpoints containing malformed or empty value elements within typed parameters.
Detection Strategies
- Inspect web server and PHP-FPM error logs for crash signatures correlated with SOAP request URIs.
- Deploy web application firewall rules that validate SOAP request structure and reject messages with missing required value elements.
- Correlate process crash telemetry with network logs to identify the source IPs sending malformed SOAP traffic.
Monitoring Recommendations
- Enable core dump collection on PHP SOAP hosts to confirm NULL pointer dereference signatures.
- Alert on sudden increases in PHP worker restarts or HTTP 5xx responses from SOAP endpoints.
- Track inbound SOAP request volumes and payload anomalies against historical baselines.
How to Mitigate CVE-2026-7262
Immediate Actions Required
- Upgrade PHP to 8.2.31, 8.3.31, 8.4.21, or 8.5.6 or later, depending on the deployed branch.
- Inventory all internet-facing and internal PHP SOAP services and identify endpoints that load a typemap.
- Restrict network exposure of SOAP endpoints to trusted clients while patching is in progress.
Patch Information
The PHP project has released fixed versions across all supported branches. Apply PHP 8.2.31, 8.3.31, 8.4.21, or 8.5.6, which contain the corrected variable check in the SOAP typemap decoder. See the PHP Security Advisory GHSA-hmxp-6pc4-f3vv for upstream patch references.
Workarounds
- Remove the typemap configuration from SoapServer instances if custom type decoding is not required.
- Place the SOAP endpoint behind a reverse proxy or WAF that enforces strict SOAP schema validation and rejects messages with missing value elements.
- Restrict access to SOAP endpoints using network ACLs, mutual TLS, or authentication at the proxy layer until patches are applied.
# Verify the installed PHP version against the fixed releases
php -v
# Example: upgrade on Debian/Ubuntu after enabling the patched repository
sudo apt update && sudo apt install --only-upgrade php8.3
# Example: upgrade on RHEL/Alma/Rocky via the Remi repository
sudo dnf module reset php -y
sudo dnf module install php:remi-8.3 -y
sudo systemctl restart php-fpm
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
