CVEs / CVE-2026-15176
CVE-2026-15176: F5 NGINX Plus vulnerability
- critical 9.2 CVSS 4.0 (from the CNA)
- EPSS 0.84% chance of exploitation in the next 30 days, higher than 57% of CVEs (30 Oct 2026)
- Last changed at its sources
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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.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| F5 NGINX Plus | from 37.1.0, before 37.1.0.1 | 37.1.0.1 |
| F5 NGINX Plus | from 37.0.0, before 37.0.5.1 | 37.0.5.1 |
| F5 NGINX Plus | from R36 onwards | — |
| F5 NGINX Plus | from R35 onwards | — |
| F5 NGINX Plus | from R34 onwards | — |
| F5 NGINX Plus | from R33 onwards | — |
| F5 NGINX Open Source | from 1.31.0, before 1.31.7 | 1.31.7 |
| F5 NGINX Open Source | from 0.1.29, before 1.30.6 | 1.30.6 |
Exploitation
Not in the CISA Known Exploited Vulnerabilities catalog as of 30 Oct 2026.
Severity
| CVSS 4.0 | 9.2 criticalCVSS: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:XScored by the CNA ([email protected]) |
|---|---|
| Weakness | CWE-122 |
On the Stackurity blog
References
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
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