FKIE_CVE-2026-42934

Vulnerability from fkie_nvd - Published: 2026-05-13 16:16 - Updated: 2026-06-18 14:07
Severity
4.8 (Medium) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L
Summary
NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_charset_module module. When charset, source_charset, and charset_map and proxy_pass with disabled buffering ("off") directives are configured, unauthenticated attackers can send requests that with conditions beyond the attackers' control to cause a heap buffer over-read in the NGINX worker process, leading to limited disclosure of memory or a restart.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
References
f5sirt@f5.comhttps://my.f5.com/manage/s/article/K000161028Mitigation, Vendor Advisory
Impacted products
Vendor Product Version
f5 dos *
f5 dos 4.8.0
f5 nginx_gateway_fabric *
f5 nginx_gateway_fabric *
f5 nginx_ingress_controller *
f5 nginx_ingress_controller *
f5 nginx_ingress_controller *
f5 nginx_instance_manager *
f5 nginx_open_source *
f5 nginx_open_source *
f5 nginx_plus *
f5 waf *
f5 waf *
f5 waf *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unknown",
          "modules": [
            "ngx_http_charset_module"
          ],
          "product": "NGINX Plus",
          "vendor": "F5",
          "versions": [
            {
              "lessThan": "*",
              "status": "unaffected",
              "version": "R37",
              "versionType": "custom"
            },
            {
              "lessThan": "R36 P4",
              "status": "affected",
              "version": "R36",
              "versionType": "custom"
            },
            {
              "lessThan": "R32 P6",
              "status": "affected",
              "version": "R32",
              "versionType": "custom"
            }
          ]
        },
        {
          "defaultStatus": "unaffected",
          "modules": [
            "ngx_http_charset_module"
          ],
          "product": "NGINX Open Source",
          "vendor": "F5",
          "versions": [
            {
              "lessThan": "*",
              "status": "unaffected",
              "version": "1.31.0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.30.1",
              "status": "affected",
              "version": "0.3.50",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "f5sirt@f5.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
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              "matchCriteriaId": "0772572C-26F9-4FA4-B9E6-BA40ED59F569",
              "versionEndIncluding": "4.7.0",
              "versionStartIncluding": "4.3.0",
              "vulnerable": true
            },
            {
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              "matchCriteriaId": "C45452BD-7A86-48E7-8E1D-1B340FF70B3B",
              "vulnerable": true
            },
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            },
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              "versionEndIncluding": "4.0.1",
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            },
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              "criteria": "cpe:2.3:a:f5:nginx_instance_manager:*:*:*:*:*:*:*:*",
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              "versionEndIncluding": "2.22.0",
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            },
            {
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              "versionEndIncluding": "1.30.0",
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              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:f5:nginx_plus:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "0B153576-468F-48C2-9BC8-922A938AB235",
              "versionEndIncluding": "r36",
              "versionStartIncluding": "r32",
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            },
            {
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              "matchCriteriaId": "F365BA5A-42D7-4024-9143-06D4DEE31212",
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              "versionEndIncluding": "5.8.0",
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            },
            {
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              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_charset_module module. When charset, source_charset, and charset_map\u00a0and proxy_pass\u00a0with disabled buffering (\"off\") directives are configured, unauthenticated attackers can send requests that with conditions beyond the attackers\u0027 control to cause a heap buffer over-read in the NGINX worker process, leading to limited disclosure of memory or a restart.\n\n\n\n\u00a0Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated."
    }
  ],
  "id": "CVE-2026-42934",
  "lastModified": "2026-06-18T14:07:22.880",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 4.8,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 2.5,
        "source": "f5sirt@f5.com",
        "type": "Secondary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 6.3,
          "baseSeverity": "MEDIUM",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:L/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",
          "version": "4.0",
          "vulnAvailabilityImpact": "LOW",
          "vulnConfidentialityImpact": "LOW",
          "vulnIntegrityImpact": "NONE",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "f5sirt@f5.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-42934",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-05-13T15:55:18.483975Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-05-13T16:16:49.910",
  "references": [
    {
      "source": "f5sirt@f5.com",
      "tags": [
        "Mitigation",
        "Vendor Advisory"
      ],
      "url": "https://my.f5.com/manage/s/article/K000161028"
    }
  ],
  "sourceIdentifier": "f5sirt@f5.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-125"
        }
      ],
      "source": "f5sirt@f5.com",
      "type": "Secondary"
    }
  ]
}


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