---
cve: "CVE-2026-56434"
severity: "HIGH"
cvss: 8.3
epss: "45%"
vendor: "F5"
kev: false
exploited: false
published: "2026-07-15 15:16:45"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-16T08:13:09+02:00"
---

# CVE-2026-56434

> 8.3 HIGH

## Beschreibung

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.

## CVSS-Vektor

```
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |

## Patch verfügbar (OSV)

- 5e34a17a8f7787e90f41d1af91258a556f0795b4 (Commit)

## Referenzen

- <https://my.f5.com/manage/s/article/K000162098>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-56434) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_