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GHSA-78JW-WW3G-9WP7

Vulnerability from github – Published: 2026-06-17 18:35 – Updated: 2026-08-25 15:32
VLAI
Details

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.

Severity
8.1 (High)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
9.2 (Critical)
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
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{
  "affected": [],
  "aliases": [
    "CVE-2026-42055"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-122",
      "CWE-131",
      "CWE-787"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-06-17T15:16:50Z",
    "severity": "CRITICAL"
  },
  "details": "NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_proxy_v2_module\u00a0and ngx_http_grpc_module\u00a0modules. This vulnerability exists when the proxy_http_version to 2\u00a0or grpc_pass\u00a0directives are used to proxy HTTP/2 traffic, the ignore_invalid_headers\u00a0directive is set to off, and the large_client_header_buffers\u00a0directive 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. \n\n\nNote: Software versions which have reached End of Technical Support (EoTS) are not evaluated.",
  "id": "GHSA-78jw-ww3g-9wp7",
  "modified": "2026-08-25T15:32:42Z",
  "published": "2026-06-17T18:35:56Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-42055"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:27197"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:36331"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:36364"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:36618"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:36639"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:38847"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:44481"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:46836"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:58981"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/security/cve/CVE-2026-42055"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2489866"
    },
    {
      "type": "WEB",
      "url": "https://my.f5.com/manage/s/article/K000161584"
    },
    {
      "type": "WEB",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42055.json"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "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/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",
      "type": "CVSS_V4"
    }
  ]
}



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