CVE-2026-42055NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_proxy_v2_module and ngx_http_grpc_module modules.
Updated under an hour ago ()
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It affects f5 dos and 10 other products. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 8.1 HIGH (v3.1, NVD)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- CWE-122, CWE-787, CWE-131
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Not given
- NVD analysis
- Modified
- Record last updated
- Sep 14, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
f5 dos f5:dos | from 4.3.0 through 4.7.0; 4.9.0 | NVD |
f5 nginx_gateway_fabric f5:nginx_gateway_fabric | from 1.3.0 through 1.6.2; from 2.0.0 through 2.6.3 | NVD |
f5 nginx_ingress_controller f5:nginx_ingress_controller | from 3.5.0 through 3.7.2; from 4.0.0 through 4.0.1; from 5.0.0 through 5.5.0 | NVD |
f5 nginx_instance_manager f5:nginx_instance_manager | from 2.17.0 through 2.22.0 | NVD |
f5 nginx_open_source f5:nginx_open_source | from 1.0.0 through 1.30.2; from 1.31.0 through 1.31.1 | NVD |
f5 nginx_plus f5:nginx_plus | from 37.0.0.1 before 37.0.2.1; from r33 before r36; r36; r36; r36; r36; r36; r36 | NVD |
f5 waf f5:waf | from 4.10.0 through 4.16.0; from 5.2.0 through 5.8.0; from 5.9.0 through 5.13.1 | NVD |
redhat discovery redhat:discovery | all versions | NVD |
redhat hardened_images redhat:hardened_images | all versions | NVD |
redhat update_infrastructure redhat:update_infrastructure | from 5.0 before 5.2 | NVD |
redhat enterprise_linux redhat:enterprise_linux | 8.0; 9.0; 10.0 | NVD |
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-tracking, third-party-advisory
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42055.jsonthird-party-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.