A vulnerability exists in NGINX Plus and NGINX Open Source when a map directive uses regex matching and a string expression 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.
References
| Link | Resource |
|---|---|
| https://my.f5.com/manage/s/article/K000162097 |
Configurations
No configuration.
History
15 Jul 2026, 15:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-07-15 15:16
Updated : 2026-07-29 05:16
NVD link : CVE-2026-42533
Mitre link : CVE-2026-42533
CVE.ORG link : CVE-2026-42533
JSON object : View
Products Affected
No product.
CWE
CWE-122
Heap-based Buffer Overflow