NGINX ngx_http_proxy_v2_module and ngx_http_grpc_module vulnerability
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Attack requirements
- Present
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-122 and the CVSS impact.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| F5 | NGINX Open Source | 1.13.10 to before 1.31.2; 1.30.2 to before 1.30.3 | 1.31.2, 1.30.3 | Patch available | CNA |
| F5 | NGINX Plus | 37.0 to before 37.0.2.1; R36 to before R36 P6 | 37.0.2.1, R36 P6 | Patch available | CNA |
- NGINX Open Source VendorF5 Affected 1.13.10 to before 1.31.2; 1.30.2 to before 1.30.3 Fixed in 1.31.2, 1.30.3 Patch available CNA
- NGINX Plus VendorF5 Affected 37.0 to before 37.0.2.1; R36 to before R36 P6 Fixed in 37.0.2.1, R36 P6 Patch available CNA
CPE configurations NVD · 21
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:f5:dos:*:*:*:*:*:nginx:*:* | 4.3.0 – 4.7.0 | Vulnerable | F5 |
| cpe:2.3:a:f5:dos:4.9.0:*:*:*:*:nginx:*:* | 4.9.0 | Vulnerable | F5 |
| cpe:2.3:a:f5:nginx_gateway_fabric:*:*:*:*:*:*:*:* | 1.3.0 – 1.6.2; 2.0.0 – 2.6.3 | Vulnerable | F5 |
| cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:continuous_releases:*:*:* | 3.5.0 – 3.7.2; 4.0.0 – 4.0.1; 5.0.0 – 5.5.0 | Vulnerable | F5 |
| cpe:2.3:a:f5:nginx_instance_manager:*:*:*:*:*:*:*:* | 2.17.0 – 2.22.0 | Vulnerable | F5 |
| cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:* | 1.0.0 – 1.30.2; 1.31.0 – 1.31.1 | Vulnerable | F5 |
| cpe:2.3:a:f5:nginx_plus:*:*:*:*:long-term_support:*:*:* | 37.0.0.1 to before 37.0.2.1 | Vulnerable | F5 |
| cpe:2.3:a:f5:nginx_plus:*:*:*:*:continuous_releases:*:*:* | r33 to before r36 | Vulnerable | F5 |
| cpe:2.3:a:f5:nginx_plus:r36:-:*:*:continuous_releases:*:*:* | r36 | Vulnerable | F5 |
| cpe:2.3:a:f5:nginx_plus:r36:p1:*:*:continuous_releases:*:*:* | r36 p1 | Vulnerable | F5 |
- cpe:2.3:a:f5:dos:*:*:*:*:*:nginx:*:* Versions 4.3.0 – 4.7.0 Vulnerable ·F5
- cpe:2.3:a:f5:dos:4.9.0:*:*:*:*:nginx:*:* Versions 4.9.0 Vulnerable ·F5
- cpe:2.3:a:f5:nginx_gateway_fabric:*:*:*:*:*:*:*:* Versions 1.3.0 – 1.6.2; 2.0.0 – 2.6.3 Vulnerable ·F5
- cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:continuous_releases:*:*:* Versions 3.5.0 – 3.7.2; 4.0.0 – 4.0.1; 5.0.0 – 5.5.0 Vulnerable ·F5
- cpe:2.3:a:f5:nginx_instance_manager:*:*:*:*:*:*:*:* Versions 2.17.0 – 2.22.0 Vulnerable ·F5
- cpe:2.3:a:f5:nginx_open_source:*:*:*:*:*:*:*:* Versions 1.0.0 – 1.30.2; 1.31.0 – 1.31.1 Vulnerable ·F5
- cpe:2.3:a:f5:nginx_plus:*:*:*:*:long-term_support:*:*:* Versions 37.0.0.1 to before 37.0.2.1 Vulnerable ·F5
- cpe:2.3:a:f5:nginx_plus:*:*:*:*:continuous_releases:*:*:* Versions r33 to before r36 Vulnerable ·F5
- cpe:2.3:a:f5:nginx_plus:r36:-:*:*:continuous_releases:*:*:* Versions r36 Vulnerable ·F5
- cpe:2.3:a:f5:nginx_plus:r36:p1:*:*:continuous_releases:*:*:* Versions r36 p1 Vulnerable ·F5
Show 11 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:f5:nginx_plus:r36:p2:*:*:continuous_releases:*:*:* | r36 p2 | Vulnerable | F5 |
| cpe:2.3:a:f5:nginx_plus:r36:p3:*:*:continuous_releases:*:*:* | r36 p3 | Vulnerable | F5 |
| cpe:2.3:a:f5:nginx_plus:r36:p4:*:*:continuous_releases:*:*:* | r36 p4 | Vulnerable | F5 |
| cpe:2.3:a:f5:nginx_plus:r36:p5:*:*:continuous_releases:*:*:* | r36 p5 | Vulnerable | F5 |
| cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:* | 4.10.0 – 4.16.0; 5.2.0 – 5.8.0; 5.9.0 – 5.13.1 | Vulnerable | F5 |
| cpe:2.3:a:redhat:discovery:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | Red Hat |
| cpe:2.3:a:redhat:hardened_images:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | Red Hat |
| cpe:2.3:a:redhat:update_infrastructure:*:*:*:*:*:*:*:* | 5.0 to before 5.2 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* | 8.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* | 9.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:* | 10.0 | Vulnerable | Red Hat |
- cpe:2.3:a:f5:nginx_plus:r36:p2:*:*:continuous_releases:*:*:* Versions r36 p2 Vulnerable ·F5
- cpe:2.3:a:f5:nginx_plus:r36:p3:*:*:continuous_releases:*:*:* Versions r36 p3 Vulnerable ·F5
- cpe:2.3:a:f5:nginx_plus:r36:p4:*:*:continuous_releases:*:*:* Versions r36 p4 Vulnerable ·F5
- cpe:2.3:a:f5:nginx_plus:r36:p5:*:*:continuous_releases:*:*:* Versions r36 p5 Vulnerable ·F5
- cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:* Versions 4.10.0 – 4.16.0; 5.2.0 – 5.8.0; 5.9.0 – 5.13.1 Vulnerable ·F5
- cpe:2.3:a:redhat:discovery:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Red Hat
- cpe:2.3:a:redhat:hardened_images:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Red Hat
- cpe:2.3:a:redhat:update_infrastructure:*:*:*:*:*:*:*:* Versions 5.0 to before 5.2 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:* Versions 10.0 Vulnerable ·Red Hat
Remediation
- Fix · CNA NGINX Open Source (F5) Fixed in 1.31.2, 1.30.3
- Fix · CNA NGINX Plus (F5) Fixed in 37.0.2.1, R36 P6
Red Hat 13 advisories
- RHSA-2026:93467 Released 2026-11-02 · Red Hat rating Importantnginx security update
- Red Hat CodeReady Linux Builder EUS (v.9.6) nginx-mod-devel-2:1.20.1-22.el9_6.7
- Red Hat Enterprise Linux AppStream EUS (v.9.6) nginx-2:1.20.1-22.el9_6.7, nginx-all-modules-2:1.20.1-22.el9_6.7, nginx-core-2:1.20.1-22.el9_6.7 +6
- RHSA-2026:93468 Released 2026-11-02 · Red Hat rating Importantnginx security update
- Red Hat Enterprise Linux AppStream E4S (v.9.4) nginx-1:1.20.1-16.el9_4.7, nginx-all-modules-1:1.20.1-16.el9_4.7, nginx-core-1:1.20.1-16.el9_4.7 +6
- RHSA-2026:93472 Released 2026-11-02 · Red Hat rating Importantnginx security update
- Red Hat Enterprise Linux AppStream E4S (v.9.2) nginx-1:1.20.1-14.el9_2.7, nginx-all-modules-1:1.20.1-14.el9_2.7, nginx-core-1:1.20.1-14.el9_2.7 +6
Show 10 more Red Hat advisories
- RHSA-2026:92650 Released 2026-10-29 · Red Hat rating ImportantRed Hat OpenShift Data Foundation 4.19.26 security, enhancement & bug fix update
- Red Hat Openshift Data Foundation 4.19 registry.redhat.io/odf4/cephcsi-rhel9, registry.redhat.io/odf4/cephcsi-rhel9-operator, registry.redhat.io/odf4/mcg-core-rhel9 +17
- RHSA-2026:58981 Released 2026-08-24 · Red Hat rating CriticalRed Hat Update Infrastructure 5.3 Technology Preview security update
- Red Hat Update Infrastructure 5 registry.redhat.io/rhui5/cds-kubernetes-tp-rhel9, registry.redhat.io/rhui5/installer-tp-rhel9, registry.redhat.io/rhui5/rhua-tp-rhel9
- RHSA-2026:46836 Released 2026-07-27 · Red Hat rating ImportantA Subscription Management tool for finding and reporting Red Hat product usage
- Red Hat Discovery 2 registry.redhat.io/discovery/discovery-server-rhel9, registry.redhat.io/discovery/discovery-ui-rhel9
- RHSA-2026:44481 Released 2026-07-23 · Red Hat rating ImportantRed Hat Update Infrastructure 5.2 security update
- Red Hat Update Infrastructure 5 registry.redhat.io/rhui5/cds-kubernetes-rhel9, registry.redhat.io/rhui5/cds-rhel9, registry.redhat.io/rhui5/haproxy-rhel9 +2
- RHSA-2026:38847 Released 2026-07-13 · Red Hat rating Importantnginx:1.24 security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 8) nginx-1:1.24.0-3.module+el8.10.0+24503+61c7c092.3.aarch64::nginx:1.24, nginx-1:1.24.0-3.module+el8.10.0+24503+61c7c092.3.ppc64le::nginx:1.24, nginx-1:1.24.0-3.module+el8.10.0+24503+61c7c092.3.s390x::nginx:1.24 +28
- RHSA-2026:36639 Released 2026-07-08 · Red Hat rating Importantnginx:1.26 security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 9) nginx-2:1.26.3-9.module+el9.8.0+24501+a1e882cd.2.aarch64::nginx:1.26, nginx-2:1.26.3-9.module+el9.8.0+24501+a1e882cd.2.ppc64le::nginx:1.26, nginx-2:1.26.3-9.module+el9.8.0+24501+a1e882cd.2.s390x::nginx:1.26 +32
- RHSA-2026:36618 Released 2026-07-08 · Red Hat rating Importantnginx:1.24 security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 9) nginx-1:1.24.0-7.module+el9.8.0+24502+c9b9ab67.3.aarch64::nginx:1.24, nginx-1:1.24.0-7.module+el9.8.0+24502+c9b9ab67.3.ppc64le::nginx:1.24, nginx-1:1.24.0-7.module+el9.8.0+24502+c9b9ab67.3.s390x::nginx:1.24 +32
- RHSA-2026:36364 Released 2026-07-07 · Red Hat rating Importantnginx security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 10) nginx-2:1.26.3-6.el10_2.5, nginx-all-modules-2:1.26.3-6.el10_2.5, nginx-core-2:1.26.3-6.el10_2.5 +6
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) nginx-mod-devel-2:1.26.3-6.el10_2.5
- RHSA-2026:36331 Released 2026-07-07 · Red Hat rating Importantnginx security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 9) nginx-2:1.20.1-28.el9_8.4, nginx-all-modules-2:1.20.1-28.el9_8.4, nginx-core-2:1.20.1-28.el9_8.4 +6
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) nginx-mod-devel-2:1.20.1-28.el9_8.4
- RHSA-2026:27197 Released 2026-06-19 · Red Hat rating ImportantRed Hat Hardened Images RPMs bug fix and enhancement update
- Red Hat Hardened Images nginx-1.30.3-2.hum1@aarch64, nginx-1.30.3-2.hum1@src, nginx-1.30.3-2.hum1@x86_64 +22
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
F5 NGINX Open Source, NGINX Plus 1.30.3, 1.31.2 and 2 more versions
2 records Highest priority Priority MEDIUM 1 MEDIUM, 1 LOW
Other records, highest priority first
- TI-2026-35579 NGINX ngx_http_charset_module vulnerabilityPriority LOW 29
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat CodeReady Linux Builder EUS (v.9.6) | Fixed | RHSA-2026:93467 |
| Red Hat Discovery 2 | Fixed | RHSA-2026:46836 |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:36364 |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2026:38847 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:36331, RHSA-2026:36618, RHSA-2026:36639 |
| Red Hat Enterprise Linux AppStream E4S (v.9.2) | Fixed | RHSA-2026:93472 |
| Red Hat Enterprise Linux AppStream E4S (v.9.4) | Fixed | RHSA-2026:93468 |
| Red Hat Enterprise Linux AppStream EUS (v.9.6) | Fixed | RHSA-2026:93467 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) | Fixed | RHSA-2026:36364 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) | Fixed | RHSA-2026:36331 |
| Red Hat Hardened Images | Fixed | RHSA-2026:27197 |
| Red Hat Openshift Data Foundation 4.19 | Fixed | RHSA-2026:92650 |
| Red Hat Update Infrastructure 5 | Fixed | RHSA-2026:44481, RHSA-2026:58981 |
Not affected: 4 products
- Red Hat Discovery 2
- Red Hat Openshift Data Foundation 4
- Red Hat Openshift Data Foundation 4.19
- Red Hat Update Infrastructure 5
Timeline
- 2026-10-02 Threatist record created from CVE-2026-42055
- 2026-10-03 Alias added: GHSA-78jw-ww3g-9wp7
- 2026-10-30 Fix available: Red Hat Openshift Data Foundation 4.19 · Red Hat
- 2026-10-31 Fix available: RHSA-2026:92650 · Red Hat
- 2026-11-02 Fix available: RHSA-2026:93468 · Red Hat
- 2026-11-02 Fix available: RHSA-2026:93472 · Red Hat
- 2026-11-02 Fix available: RHSA-2026:93467 · Red Hat
- 2026-11-02 Fix available: Red Hat CodeReady Linux Builder EUS (v.9.6), Red Hat Enterprise Linux AppStream E4S (v.9.2), Red Hat Enterprise Linux AppStream E4S (v.9.4) +1 · Red Hat
References
Advisory 12
- https://my.f5.com/manage/s/article/K000161584
- https://access.redhat.com/errata/RHSA-2026:27197
- https://access.redhat.com/errata/RHSA-2026:36331
- https://access.redhat.com/errata/RHSA-2026:36364
- https://access.redhat.com/errata/RHSA-2026:36618
- https://access.redhat.com/errata/RHSA-2026:36639
- https://access.redhat.com/errata/RHSA-2026:38847
- https://access.redhat.com/errata/RHSA-2026:44481
- https://access.redhat.com/errata/RHSA-2026:46836
- https://access.redhat.com/security/cve/CVE-2026-42055
- https://bugzilla.redhat.com/show_bug.cgi?id=2489866
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42055.json
More F5 Dos vulnerabilities
- TI-2026-31136 NGINX ngx_http_rewrite_module vulnerability CVSS 4.0CRITICAL 9.2
- TI-2026-08132 NGINX ngx_http_rewrite_module vulnerability CVSS 4.0CRITICAL 9.2
- TI-2026-31137 NGINX ngx_http_scgi_module and ngx_http_uwsgi_module vulnerability CVSS 4.0HIGH 8.3
- TI-2026-29212 NGINX ngx_quic_module vulnerability CVSS 4.0MEDIUM 6.9
- TI-2026-35579 NGINX ngx_http_charset_module vulnerability CVSS 4.0MEDIUM 6.3
- TI-2026-31131 NGINX ngx_http_charset_module vulnerability CVSS 4.0MEDIUM 6.3
Sources
- CVE-2026-42055 · CVE Program
- CVE-2026-42055 · NVD
- FIRST EPSS
- GHSA-78jw-ww3g-9wp7 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-42055 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences