CVE-2026-93479
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 code (if ASLR is disabled or bypassed) by sending crafted HTTP requests. They only need network access to the exposed HTTP/HTTPS port.
Root cause
A heap-based buffer overflow occurs when referencing regex capture variables or non-cacheable variables in directives like root or access log format before evaluating the map output variable.
Affected systems
Versions not listed — check the vendor advisory.
CVSS v3.1 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Fix & remediation
Upgrade to the patched NGINX release once specified by the vendor. As an interim workaround, reorder your configuration to reference the map's output variable before using its regex capture variables in the root directive or access_log format.
$ nginx -T | grep -E '(map|root|access_log)'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 map directive uses regex matching and the root directive or access log format references the map's regex capture variables before referencing the map output variable. Alternatively, the same result could be achieved by using a non-cacheable variable in a string expression under certain conditions. 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.