SECURELYN

CVE-2026-15176

A vulnerability exists in NGINX Plus and NGINX Open Source when a location is configured that uses the alias directive together with rewrite and a set or return directive referencing the $request_filename variable. Alternatively, the same result could be achieved when the $request_filename variable is used in an access log format directive. An unauthenticated attacker along with conditions beyond their control can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can exec…

Scores

9.2
CVSS 9.2 out of 10, critical severity.
0.5%
EPSS 0.5% chance of exploitation in the next 30 days.

The facts

Published
14 October 2026
Last changed
15 October 2026
NVD status
Awaiting Analysis
Severity
Critical, CVSS 9.2 out of 10 (version 4.0)
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R…
Weakness
Known exploited
Not in the CISA Known Exploited Vulnerabilities catalogue in this build.
EPSS
0.5% chance of exploitation activity in the next 30 days (percentile 43).

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References