CVE-2026-15176
8.1HighPublished 14 Oct 2026 · NVD status: Awaiting Analysis · AI triage by gemini-3.8-flash
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
- Impact
- Full C/I/A compromise
- Weakness
- CWE-122
Impact
Remote, unauthenticated attackers can crash NGINX worker processes or potentially execute arbitrary code if ASLR is disabled or bypassed. They only need network access to send specially crafted HTTP requests to vulnerable locations.
Root cause
A heap-based buffer overflow occurs when the alias directive is combined with rewrite and set/return directives referencing $request_filename, or when $request_filename is used in an access log format.
Affected systems
NGINX Open Source and NGINX Plus (exact version ranges not listed — check vendor advisory K000162416).
CVSS v3.1 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Fix & remediation
Check the vendor advisory for patch versions; to mitigate immediately, remove references to $request_filename in log formats and avoid combining alias with rewrite and set/return directives referencing $request_filename.
$ grep -rnE '(\$request_filename|alias)' /etc/nginx/AI-suggested. Run it in staging first and check it against the vendor advisory. Why?
NVD description
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 execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR. Impact: This vulnerability may allow remote attackers to cause a denial-of-service (DoS) on the NGINX system or to possibly trigger a code execution. There is no control plane exposure; this is a data plane issue only. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.