CVE-2026-42533 (GCVE-0-2026-42533)
Vulnerability from cvelistv5
Published
2026-07-15 14:33
Modified
2026-07-29 03:55
Severity ?
8.1 (High) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
9.2 (Critical) - 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
CWE
  • CWE-122 - Heap-based Buffer Overflow
Summary
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
Impacted products
Vendor Product Version
F5 NGINX Plus Version: 37.0.0.1   < 37.0.3.1
Version: R36   < R36 P7
Version: R33   < *
 Create a notification for this product.
   F5 NGINX Open Source Version: 1.31.2   < 1.31.3
Version: 0.9.6   < 1.30.4
 Create a notification for this product.
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