CVE search · CVE-2026-42533
CVE-2026-42533
critical 9.2
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.
Details
- Status
- Analyzed
- Published
- Last changed
- Source
- f5sirt@f5.com
- Weakness
- CWE-122
Severity
| Version | Score | Vector | Source |
|---|---|---|---|
| CVSS 4.0 | critical 9.2 | 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:X/V:X/RE:X/U:X |
f5sirt@f5.comSecondary |
| CVSS 3.1 | high 8.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
f5sirt@f5.comSecondary |
Affected products
Vendor and product from the NVD’s CPE applicability statements. Versions and conditions are on the NVD’s page.
References
- https://my.f5.com/manage/s/article/K000162097Vendor Advisory