CVE detail
CVE-2026-42055
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.
Buzz score
Why this CVE is surfacing
This all-time snapshot uses the same composite formula as Trending across a 30-year evidence window, rather than a current rolling window.
Buzz score components · mention 27.7 · diversity 20.0 · KEV 0.0 · OTX 0.0 · PoC 0.0
Why it matters now
Mention timeline
- Total mentions
- 1
- within the 30d window
- Peak daily
- 1
- highest bucket
Evidence
Source links by recency
15 source links · newest first
Information published.
vendormsrc.microsoft.comJul 1, 2026, 8:01 AMF5 released emergency updates for critical NGINX flaws (CVE-2026-42530, CVE-2026-42055) that could enable unauthenticated code execution. F5 has issued out-of-band patches for multiple NGINX vulnerabilities, including two critical flaws, respectively tracked as CVE-2026-42530 and CVE-2026-42055 (CVSS 9.2). The bugs affect HTTP modules and can be exploited remotely without authentication to trigger memory corruption, potentially causing […]
newssecurityaffairs.comJun 18, 2026, 2:07 PMCritical flaws in NGINX could allow remote, unauthenticated attackers to cause a restart and potentially execute arbitrary code.
newswww.securityweek.comJun 18, 2026, 9:39 AM- https://access.redhat.com/errata/RHSA-2026:46836access.redhat.com
No excerpt available.
Vendor Advisoryaccess.redhat.comJun 17, 2026, 3:16 PM - https://access.redhat.com/errata/RHSA-2026:44481access.redhat.com
No excerpt available.
Vendor Advisoryaccess.redhat.comJun 17, 2026, 3:16 PM - https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42055.jsonsecurity.access.redhat.com
No excerpt available.
Vendor Advisorysecurity.access.redhat.comJun 17, 2026, 3:16 PM - https://bugzilla.redhat.com/show_bug.cgi?id=2489866bugzilla.redhat.com
No excerpt available.
Exploitbugzilla.redhat.comJun 17, 2026, 3:16 PM - https://access.redhat.com/security/cve/CVE-2026-42055access.redhat.com
No excerpt available.
Vendor Advisoryaccess.redhat.comJun 17, 2026, 3:16 PM - https://access.redhat.com/errata/RHSA-2026:38847access.redhat.com
No excerpt available.
Vendor Advisoryaccess.redhat.comJun 17, 2026, 3:16 PM - https://access.redhat.com/errata/RHSA-2026:36639access.redhat.com
No excerpt available.
Vendor Advisoryaccess.redhat.comJun 17, 2026, 3:16 PM - https://access.redhat.com/errata/RHSA-2026:36618access.redhat.com
No excerpt available.
Vendor Advisoryaccess.redhat.comJun 17, 2026, 3:16 PM - https://access.redhat.com/errata/RHSA-2026:36364access.redhat.com
No excerpt available.
Vendor Advisoryaccess.redhat.comJun 17, 2026, 3:16 PM - https://access.redhat.com/errata/RHSA-2026:36331access.redhat.com
No excerpt available.
Vendor Advisoryaccess.redhat.comJun 17, 2026, 3:16 PM - https://access.redhat.com/errata/RHSA-2026:27197access.redhat.com
No excerpt available.
Vendor Advisoryaccess.redhat.comJun 17, 2026, 3:16 PM No excerpt available.
Vendor Advisorymy.f5.comJun 17, 2026, 3:16 PM
Exploit code
Public exploit repository references
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0 repository references · best confidence N/A · max 0 stars
Related records
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When NGINX Plus or NGINX Open Source are configured to use the HTTP/3 QUIC module, an attacker may be able to spoof their source IP address allowing for bypass of authorization or…