Bug 2489866 (CVE-2026-42055) - CVE-2026-42055 nginx: NGINX: Arbitrary code execution or Denial of Service via heap-based buffer overflow with crafted HTTP/2 headers
Summary: CVE-2026-42055 nginx: NGINX: Arbitrary code execution or Denial of Service vi...
Keywords:
Status: NEW
Alias: CVE-2026-42055
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On: 2492053
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-06-17 16:02 UTC by OSIDB Bzimport
Modified: 2026-07-13 10:45 UTC (History)
3 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2026:36331 0 None None None 2026-07-07 18:58:37 UTC
Red Hat Product Errata RHSA-2026:36364 0 None None None 2026-07-07 21:30:14 UTC
Red Hat Product Errata RHSA-2026:36618 0 None None None 2026-07-08 10:06:23 UTC
Red Hat Product Errata RHSA-2026:36639 0 None None None 2026-07-08 11:39:39 UTC
Red Hat Product Errata RHSA-2026:38847 0 None None None 2026-07-13 10:45:27 UTC

Description OSIDB Bzimport 2026-06-17 16:02:04 UTC
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.

Comment 2 errata-xmlrpc 2026-07-07 18:58:37 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:36331 https://access.redhat.com/errata/RHSA-2026:36331

Comment 3 errata-xmlrpc 2026-07-07 21:30:13 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:36364 https://access.redhat.com/errata/RHSA-2026:36364

Comment 5 errata-xmlrpc 2026-07-08 10:06:22 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:36618 https://access.redhat.com/errata/RHSA-2026:36618

Comment 6 errata-xmlrpc 2026-07-08 11:39:38 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

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

Comment 7 errata-xmlrpc 2026-07-13 10:45:26 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:38847 https://access.redhat.com/errata/RHSA-2026:38847


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