Buffer overflow in F5 Dos
CVE-2026-42055
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_proxy_v2_module and ngx_http_grpc_module modules. This vulnerability exists when the proxy_http_version to 2 or grpc_pass directives are used to proxy HTTP/2 traffic, th…
Vulnerability class: Buffer Overflow
EPSS: 0.040 (89.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- F5 Dos — versions 4.9.0
- F5 Nginx_app_protect_dos
- F5 Nginx_app_protect_waf
- F5 Nginx_gateway_fabric
- F5 Nginx_ingress_controller — versions 4.0.0, 4.0.1
- F5 Nginx_instance_manager
- F5 Nginx Open Source — versions 1.13.10, 1.30.2
- F5 Nginx_open_source — versions 1.31.1
- F5 Nginx Plus — versions 37.0, R36
- F5 Nginx_plus — versions r3, r30, r31
Weakness classification (CWE)
Public proof-of-concept exploits
References
- f5sirt@f5.com (vendor-advisory, Vendor Advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Third Party Advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Third Party Advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Third Party Advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Third Party Advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Frequently asked questions
- What is CVE-2026-42055?
- CVE-2026-42055 is a high-severity vulnerability in F5 Dos, classified under Heap-based Buffer Overflow. CVSS score: 8.1/10. Published 2026-06-17.
- How severe is CVE-2026-42055?
- High severity. CVSS v3 base score is 8.1 out of 10.
- Is CVE-2026-42055 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.