---
cve: "CVE-2026-42530"
severity: "CRITICAL"
cvss: 9.2
epss: "1.1%"
vendor: "F5"
kev: false
exploited: false
published: "2026-06-17 15:16:50"
tags: [cve, security, critical]
source: tsecurity.de CVE-Dossier
exported: "2026-10-25T22:51:27+01:00"
---

# CVE-2026-42530

> 9.2 CRITICAL

## Beschreibung

NGINX Open Source has a vulnerability in the ngx_http_v3_module module. When NGINX Open Source is configured to use the HTTP/3 QUIC module, a remote unauthenticated attacker along with conditions beyond their control can use a specially crafted HTTP/3 session to reopen a QPACK encoder stream. This may cause a Use-after-Free 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.  


Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

## CNA-Record (Kanon, cvelistV5)

- CNA: **f5**
- State: PUBLISHED
- Stand: 2026-07-16 12:04:40
- CNA-CVSS: **8.1** (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H`)

## CISA-Anreicherung (vulnrichment/ADP)

- CISA-SSVC (Coordinator, v2.0.3):
  - Exploitation: **none**
  - Automatable: **no**
  - Technical Impact: **total**

## CVSS-Vektor

```
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
```

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

## Schwachstellen-Klasse

- **CWE-416** — Use After Free
  The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

## Patch verfügbar (OSV)

- 2fd01ed47a1fd2965754c83f53b33a789d0e07f1 (Commit)
- 66691213cd771fe56b124786ea6701c7fb8e467a (Commit)

## BSI-Hinweise (deutsch)

- [NGINX und NGINX Plus: Mehrere Schwachstellen](https://wid.cert-bund.de/portal/wid/sicherheitshinweis/WID-SEC-W-2026-1995) — _BSI-Einstufung: hoch_
  Ein Angreifer kann mehrere Schwachstellen in NGINX und NGINX NGINX Plus ausnutzen, um Daten zu manipulieren, beliebigen Code auszuführen, vertrauliche Informationen offenzulegen oder einen Denial-of-Service-Zustand auszulösen.

## Referenzen

- <https://my.f5.com/manage/s/article/K000161616>
- <https://access.redhat.com/errata/RHSA-2026:20351>
- <https://access.redhat.com/security/cve/CVE-2026-42530>
- <https://bugzilla.redhat.com/show_bug.cgi?id=2489872>
- <https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42530.json>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/sicherheitsluecken/cve-2026-42530/) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI WID (CSAF)_