Medium · published July 15, 2026
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_ssi_module module. This vulnerability may exist when the Server-Side Includes (SSI), proxy_pass, and proxy_buffering off directives are configured. With this configuration, an unauthenticated attacker with man-in-the-middle (MITM) ability to control responses from an upstream server may be able to cause a use-after-free in the NGINX worker process. This issue may lead to limited modification of memory or a restart of the NGINX worker process.
Impact:
This vulnerability may allow remote attackers to have limited control to modify memory contents or restart the NGINX worker process. 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.
| Product | Versions | Fixed in |
|---|---|---|
| f5/nginx_gateway_fabric | ≥ 1.3.0, ≤ 1.6.2 | — |
| f5/nginx_gateway_fabric | ≥ 2.0.0, < 2.6.7 | 2.6.7 |
| f5/nginx_ingress_controller | ≥ 3.5.0, ≤ 3.7.2 | — |
| f5/nginx_ingress_controller | ≥ 5.0.0, < 5.5.3 | 5.5.3 |
| f5/nginx_ingress_controller | ≥ 2026-lts-r1, < 2026-lts-r4 | 2026-lts-r4 |
| f5/nginx_ingress_controller | all versions | — |
| f5/nginx_ingress_controller | all versions | — |
| f5/nginx_plus | ≥ 37.0.0.1, < 37.0.3.1 | 37.0.3.1 |
| f5/nginx_plus | ≥ r33, < r36 | r36 |
| f5/nginx_plus | all versions | — |
| f5/nginx_plus | all versions | — |
| f5/nginx_plus | all versions | — |
| f5/nginx_plus | all versions | — |
| f5/nginx_plus | all versions | — |
| f5/nginx_plus | all versions | — |
| f5/nginx_plus | all versions | — |
| f5/waf | ≥ 4.11.0, ≤ 4.16.0 | — |
| f5/waf | ≥ 5.2.0, ≤ 5.8.0 | — |
| f5/waf | ≥ 5.9.0, < 5.13.4 | 5.13.4 |