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CVE-2026-73857

Full vulnerability record from the local CVENow database.

Description

ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. From 3.0.15 until 3.0.17, XML request body processing with SecParseXmlIntoArgs set to On or OnlyArgs can leave XMLNodes::parsing_ctx_arg uninitialized in the SAX end-element callback. A single crafted unauthenticated HTTP request can make a worker dereference the pointer, resulting in a constant-value write to an attacker-controlled address. The resulting memory corruption can terminate the worker and may disclose memory or redirect execution. Earlier 3.0.x releases and ModSecurity 2.x do not use the affected path. This issue is fixed in version 3.0.17.

Severity
HIGH
CVSS score
7.5 (v3.1)
Vulnerability status
Received
Source identifier
Published
2026-11-09 22:18:54.253000
Last modified
2026-11-09 22:18:54.253000
View original CVE JSON
{
  "id": "CVE-2026-73857",
  "sourceIdentifier": "[email protected]",
  "published": "2026-11-09T22:18:54.253",
  "lastModified": "2026-11-09T22:18:54.253",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "ModSecurity is an open source, cross platform web application firewall (WAF) engine for Apache, IIS and Nginx. From 3.0.15 until 3.0.17, XML request body processing with SecParseXmlIntoArgs set to On or OnlyArgs can leave XMLNodes::parsing_ctx_arg uninitialized in the SAX end-element callback. A single crafted unauthenticated HTTP request can make a worker dereference the pointer, resulting in a constant-value write to an attacker-controlled address. The resulting memory corruption can terminate the worker and may disclose memory or redirect execution. Earlier 3.0.x releases and ModSecurity 2.x do not use the affected path. This issue is fixed in version 3.0.17."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "owasp-modsecurity",
          "product": "ModSecurity",
          "versions": [
            {
              "version": ">= 3.0.15, < 3.0.17",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-787"
        },
        {
          "lang": "en",
          "value": "CWE-824"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/owasp-modsecurity/ModSecurity/commit/e979a73e89d60cefdf42b41bb38bf1e456d7909f",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/owasp-modsecurity/ModSecurity/releases/tag/v3.0.17",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/owasp-modsecurity/ModSecurity/security/advisories/GHSA-jx3r-phvx-2jmj",
      "source": "[email protected]"
    }
  ]
}