CVE search · CVE-2026-42055
CVE-2026-42055
critical 9.2
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, the ignore_invalid_headers directive is set to off, and the large_client_header_buffers directive size is larger than 2 megabytes. A remote, unauthenticated attacker, along with conditions beyond their control, could send large headers while creating an upstream request. This may cause a heap-based 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. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Details
- Status
- Modified
- Published
- Last changed
- Source
- f5sirt@f5.com
Severity
| Version | Score | Vector | Source |
|---|---|---|---|
| CVSS 4.0 | critical 9.2 | CVSS:4.0/AV:N/AC:H/AT:P/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:X |
f5sirt@f5.comSecondary |
| CVSS 3.1 | high 8.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
f5sirt@f5.comSecondary |
| CVSS 3.1 | high 8.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
0b0ca135-0b70-47e7-9f44-1890c2a1c46cSecondary |
Affected products
Vendor and product from the NVD’s CPE applicability statements. Versions and conditions are on the NVD’s page.
- f5 · dos
- f5 · nginx_gateway_fabric
- f5 · nginx_ingress_controller
- f5 · nginx_instance_manager
- f5 · nginx_open_source
- f5 · nginx_plus
- f5 · waf
- redhat · discovery
- redhat · hardened_images
- redhat · update_infrastructure
- redhat · enterprise_linux
References
- https://my.f5.com/manage/s/article/K000161584Vendor Advisory
- https://access.redhat.com/errata/RHSA-2026:27197Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:36331Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:36364Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:36618Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:36639Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:38847Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:44481Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:46836Third Party Advisory
- https://access.redhat.com/errata/RHSA-2026:58981
- https://access.redhat.com/security/cve/CVE-2026-42055Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2489866Issue TrackingThird Party Advisory
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42055.jsonThird Party Advisory