Heap-based buffer overflow in NGINX Open Source and NGINX Plus - CVE-2026-27654
Published: March 25, 2026 / Updated: May 22, 2026
Vulnerability identifier: #VU124478
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:P/U:Green
CVE-ID: CVE-2026-27654
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability:
Public exploit is available
Vendor: F5 Networks
Affected software:
NGINX Open Source
NGINX Plus
NGINX Open Source
NGINX Plus
Detailed vulnerability description
The vulnerability allows a remote attacker to perform a denial of service attack.
The vulnerability exists due to a boundary error in the ngx_http_dav_module module. A remote attacker can send specially crafted request to the server, trigger a heap-based buffer overflow and perform a denial of service attack or modify source or destination file names outside the document root.
How to mitigate CVE-2026-27654
Install updates from vendor's website.