CVE-2026-27654
HighCVSS 8.2Exploitation Probability (EPSS)
Very high risk97th percentile - higher than 97% of all known CVEs
Summary
A vulnerability in the NGINX ngx_http_dav_module allows an attacker to trigger a buffer overflow in the NGINX worker process. The issue occurs when the configuration uses MOVE or COPY methods with alias directives and prefix locations.
Risk Assessment
The attack may cause termination of the NGINX worker process or modification of file names outside the document root, leading to data integrity issues. Risk is limited due to the low privileges of the worker process.
Recommendation
Immediately update NGINX to a patched version. If not possible, temporarily avoid using MOVE and COPY methods with alias directives in the configuration.
Original NVD description (English source)
NGINX Open Source and NGINX Plus have a vulnerability in the ngx_http_dav_module module that might allow an attacker to trigger a buffer overflow to the NGINX worker process; this vulnerability may result in termination of the NGINX worker process or modification of source or destination file names outside the document root. This issue affects NGINX Open Source and NGINX Plus when the configuration file uses DAV module MOVE or COPY methods, prefix location (nonregular expression location configuration), and alias directives. The integrity impact is constrained because the NGINX worker process user has low privileges and does not have access to the entire system. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.