NVD

CVE-2026-42055 Detail

Modified After Enrichment

This CVE record has been updated after NVD enrichment efforts were completed. Enrichment data supplied by the NVD may require amendment due to these changes.

Description

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.

Metrics

NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.

CVSS 4.0 Severity and Vector Strings:

NIST: NVD

N/A

NVD assessment not yet provided.

Nist CVSS score does not match with CNA score

CNA: F5 Networks

CVSS-B 9.2 CRITICAL

Vector: 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

CVSS 3.x Severity and Vector Strings:

CNA: F5 Networks

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

ADP: redhat-SADP

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

CVSS 2.0 Severity and Vector Strings:

National Institute of Standards and Technology

NIST: NVD

Base Score: N/A

NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL	Source(s)	Tag(s)
https://access.redhat.com/errata/RHSA-2026:27197	redhat-SADP	Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:36331	redhat-SADP
https://access.redhat.com/errata/RHSA-2026:36364	redhat-SADP
https://access.redhat.com/errata/RHSA-2026:36618	redhat-SADP
https://access.redhat.com/errata/RHSA-2026:36639	redhat-SADP
https://access.redhat.com/security/cve/CVE-2026-42055	redhat-SADP	Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2489866	redhat-SADP	Third Party Advisory
https://my.f5.com/manage/s/article/K000161584	F5 Networks	Vendor Advisory
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42055.json	redhat-SADP	Third Party Advisory

Weakness Enumeration

CWE-ID	CWE Name	Source
CWE-787	Out-of-bounds Write	NIST
CWE-122	Heap-based Buffer Overflow	F5 Networks
CWE-131	Incorrect Calculation of Buffer Size	redhat-SADP

Known Affected Software Configurations Switch to CPE 2.2

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Change History

7 change records found show changes

CVE Modified by redhat-SADP 7/09/2026 9:17:08 AM

Action

Type

Old Value

New Value

Added

Reference

https://access.redhat.com/errata/RHSA-2026:36639

Changed

Affected

[{"vendor":"Red Hat","product":"Red Hat Enterprise Linux AppStream (v. 10)","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:10.2"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux AppStream (v. 9)","defaultStatus":"affected","cpes":["cpe:/a:redhat:enterprise_linux:9::appstream"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:10.2"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)","defaultStatus":"affected","cpes":["cpe:/a:redhat:enterprise_linux:9::crb"]},{"vendor":"Red Hat","product":"Red Hat Hardened Images","defaultStatus":"affected","cpes":["cpe:/a:redhat:hummingbird:1"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:8"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:9"]},{"vendor":"Red Hat","product":"Red Hat Openshift Data Foundation 4","defaultStatus":"affected","cpes":["cpe:/a:redhat:openshift_data_foundation:4"]}]

[{"vendor":"Red Hat","product":"Red Hat Enterprise Linux AppStream (v. 10)","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:10.2"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux AppStream (v. 9)","defaultStatus":"affected","cpes":["cpe:/a:redhat:enterprise_linux:9::appstream"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:10.2"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)","defaultStatus":"affected","cpes":["cpe:/a:redhat:enterprise_linux:9::crb"]},{"vendor":"Red Hat","product":"Red Hat Hardened Images","defaultStatus":"affected","cpes":["cpe:/a:redhat:hummingbird:1"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:8"]},{"vendor":"Red Hat","product":"Red Hat Openshift Data Foundation 4","defaultStatus":"affected","cpes":["cpe:/a:redhat:openshift_data_foundation:4"]}]

CVE Modified by redhat-SADP 7/08/2026 9:16:43 AM

Action	Type	Old Value	New Value
Added	Reference		https://access.redhat.com/errata/RHSA-2026:36331
Added	Reference		https://access.redhat.com/errata/RHSA-2026:36364
Added	Reference		https://access.redhat.com/errata/RHSA-2026:36618
Changed	Affected	[{"vendor":"Red Hat","product":"Red Hat Hardened Images","defaultStatus":"affected","cpes":["cpe:/a:redhat:hummingbird:1"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 10","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:10"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:8"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:9"]}]	[{"vendor":"Red Hat","product":"Red Hat Enterprise Linux AppStream (v. 10)","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:10.2"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux AppStream (v. 9)","defaultStatus":"affected","cpes":["cpe:/a:redhat:enterprise_linux:9::appstream"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:10.2"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)","defaultStatus":"affected","cpes":["cpe:/a:redhat:enterprise_linux:9::crb"]},{"vendor":"Red Hat","product":"Red Hat Hardened Images","defaultStatus":"affected","cpes":["cpe:/a:redhat:hummingbird:1"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:8"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:9"]},{"vendor":"Red Hat","product":"Red Hat Openshift Data Foundation 4","defaultStatus":"affected","cpes":["cpe:/a:redhat:openshift_data_foundation:4"]}]

Initial Analysis by NIST 7/02/2026 4:03:31 PM

Action	Type	New Value
Added	CWE	CWE-787
Added	CPE Configuration	Record truncated, showing 2048 of 3093 characters. View Entire Change Record OR cpe:2.3:a:f5:nginx_plus:r30:-::::::* cpe:2.3:a:f5:nginx_plus:r31:p1::::::* cpe:2.3:a:f5:nginx_plus:r30:p2::::::* cpe:2.3:a:f5:nginx_plus:r31:-::::::* cpe:2.3:a:f5:nginx_plus:r32:-::::::* cpe:2.3:a:f5:nginx_plus:r30:p1::::::* cpe:2.3:a:f5:nginx_plus:r32:p1::::::* cpe:2.3:a:f5:nginx_plus:r32:p2::::::* cpe:2.3:a:f5:nginx_plus:r33:-::::::* cpe:2.3:a:f5:nginx_plus:r33:p1::::::* cpe:2.3:a:f5:nginx_plus:r33:p2::::::* cpe:2.3:a:f5:nginx_plus:r34:-::::::* cpe:2.3:a:f5:nginx_plus:r34:p1::::::* cpe:2.3:a:f5:nginx_plus:r32:p3::::::* cpe:2.3:a:f5:nginx_plus:r33:p3::::::* cpe:2.3:a:f5:nginx_plus:r34:p2::::::* cpe:2.3:a:f5:nginx_plus:r35:-::::::* cpe:2.3:a:f5:nginx_plus:r36:-::::::* cpe:2.3:a:f5:nginx_plus:r36:p1::::::* cpe:2.3:a:f5:nginx_plus:r35:p1::::::* cpe:2.3:a:f5:nginx_plus:r36:p2::::::* cpe:2.3:a:f5:nginx_plus:r32:p4::::::* cpe:2.3:a:f5:nginx_app_protect_dos::::::::* versions from (including) 4.3.0 up to (including) 4.7.0 cpe:2.3:a:f5:nginx_gateway_fabric::::::::* versions from (including) 1.3.0 up to (including) 1.6.2 cpe:2.3:a:f5:nginx_ingress_controller::::::::* versions from (including) 3.5.0 up to (including) 3.7.2 cpe:2.3:a:f5:dos:4.9.0:::::nginx::* cpe:2.3:a:f5:nginx_instance_manager::::::::* versions from (including) 2.17.0 up to (including) 2.22.0 cpe:2.3:a:f5:nginx_plus::::::::* versions from (including) 37.0.0 up to (including) 37.0.1 cpe:2.3:a:f5:waf::::::nginx:: versions from (including) 5.9.0 up to (including) 5.13.1 cpe:2.3:a:f5:nginx_gateway_fabric::::::::* versions from (including) 2.0.0 up to (excluding) 2.6.4
Added	Reference Type	F5 Networks: https://my.f5.com/manage/s/article/K000161584 Types: Vendor Advisory
Added	Reference Type	redhat-SADP: https://access.redhat.com/errata/RHSA-2026:27197 Types: Third Party Advisory
Added	Reference Type	redhat-SADP: https://access.redhat.com/security/cve/CVE-2026-42055 Types: Third Party Advisory
Added	Reference Type	redhat-SADP: https://bugzilla.redhat.com/show_bug.cgi?id=2489866 Types: Third Party Advisory
Added	Reference Type	redhat-SADP: https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42055.json Types: Third Party Advisory

CVE Modified by redhat-SADP 6/29/2026 11:19:33 PM

Action	Type	New Value
Added	CVSS V3.1	AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Added	CWE	CWE-131
Added	Reference	https://access.redhat.com/errata/RHSA-2026:27197
Added	Reference	https://access.redhat.com/security/cve/CVE-2026-42055
Added	Reference	https://bugzilla.redhat.com/show_bug.cgi?id=2489866
Added	Reference	https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42055.json
Added	Affected	[{"vendor":"Red Hat","product":"Red Hat Hardened Images","defaultStatus":"affected","cpes":["cpe:/a:redhat:hummingbird:1"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 10","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:10"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:8"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:9"]}]

New CVE Received from F5 Networks 6/17/2026 11:16:50 AM

Action	Type	New Value
Added	Description	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.
Added	CVSS V4.0	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
Added	CVSS V3.1	AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Added	CWE	CWE-122
Added	Reference	https://my.f5.com/manage/s/article/K000161584
Added	Affected	[{"vendor":"F5","product":"NGINX Open Source","defaultStatus":"unknown","modules":["ngx_http_proxy_v2_module","ngx_http_grpc_module"],"versions":[{"version":"1.13.10","lessThan":"1.31.2","versionType":"custom","status":"affected"},{"version":"1.30.2","lessThan":"1.30.3","versionType":"custom","status":"affected"}]},{"vendor":"F5","product":"NGINX Plus","defaultStatus":"unaffected","modules":["ngx_http_proxy_v2_module","ngx_http_grpc_module"],"versions":[{"version":"37.0","lessThan":"37.0.2.1","versionType":"custom","status":"affected"},{"version":"R36","lessThan":"R36 P6","versionType":"custom","status":"affected"}]}]

Quick Info

CVE Dictionary Entry:
CVE-2026-42055
NVD Published Date:
06/17/2026
NVD Last Modified:
07/09/2026
Source:
F5 Networks

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