CVE-2026-121727 (GCVE-0-2026-121727)

Vulnerability from cvelistv5 – Published: 2026-11-03 22:55 – Updated: 2026-11-03 22:55
VLAI
Title
Kore before 4.3.0 Integer Underflow Memory Exhaustion via http_header_recv()
Summary
Kore before 4.3.0 contains an integer underflow vulnerability in HTTP request body handling that allows unauthenticated attackers to bypass http_body_max by sending more body bytes than declared. Attackers can send oversized first segments over many concurrent POST, PUT or DELETE connections, wrapping content_length to grow buffers unbounded and exhaust worker memory.
Severity
8.7 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE
  • CWE-191 - Integer Underflow (Wrap or Wraparound)
Assigner
VulnCheck CNA under the mitre root
CNA scorecard B 84/100 over 7427 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
jorisvink kore Affected: 0 , < 4.3.0 (semver)
guessed Create a notification for this product.
Date Public
2026-09-02 00:00
Credits
Tristan Madani Joris Vink
Show details on NVD website
To clipboard 

{
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          "product": "kore",
          "vendor": "jorisvink",
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              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
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        }
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      "credits": [
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          "lang": "en",
          "type": "finder",
          "value": "Tristan Madani"
        },
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          "type": "remediation developer",
          "value": "Joris Vink"
        }
      ],
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        }
      ],
      "metrics": [
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            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
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            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
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          "descriptions": [
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              "description": "Integer Underflow (Wrap or Wraparound)",
              "lang": "en",
              "type": "CWE"
            }
          ]
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      ],
      "providerMetadata": {
        "dateUpdated": "2026-11-03T22:55:33.948Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
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      "references": [
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          "name": "Patch Commit",
          "tags": [
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          "url": "https://github.com/jorisvink/kore/commit/1ff3c0f6f7973dc7fc8bf38369790ef2d8079b3b"
        },
        {
          "tags": [
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          ],
          "url": "https://github.com/jorisvink/kore"
        },
        {
          "name": "Kore 4.3.0 Release Notes",
          "tags": [
            "release-notes"
          ],
          "url": "https://kore.io/releases/4.3.0"
        },
        {
          "tags": [
            "technical-description"
          ],
          "url": "https://github.com/jorisvink/kore/blob/4.3.0-rc5/src/http.c#L934"
        },
        {
          "name": "VulnCheck Advisory: Kore before 4.3.0 Integer Underflow Memory Exhaustion via http_header_recv()",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/kore-before-4.3.0-integer-underflow-memory-exhaustion-via-http-header-recv"
        }
      ],
      "title": "Kore before 4.3.0 Integer Underflow Memory Exhaustion via http_header_recv()",
      "x_generator": {
        "engine": "vulncheck-endgame"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-121727",
    "datePublished": "2026-11-03T22:55:33.948Z",
    "dateReserved": "2026-11-03T22:17:02.851Z",
    "dateUpdated": "2026-11-03T22:55:33.948Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
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      "date": "2026-11-06",
      "epss": "0.00389",
      "percentile": "0.3324"
    },
    "nvd": {
      "cve": {
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            "affectedData": [
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                "defaultStatus": "unaffected",
                "packageURL": "pkg:github/jorisvink/kore",
                "product": "kore",
                "vendor": "jorisvink",
                "versions": [
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                    "status": "affected",
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            "source": "disclosure@vulncheck.com"
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        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "Kore before 4.3.0 contains an integer underflow vulnerability in HTTP request body handling that allows unauthenticated attackers to bypass http_body_max by sending more body bytes than declared. Attackers can send oversized first segments over many concurrent POST, PUT or DELETE connections, wrapping content_length to grow buffers unbounded and exhaust worker memory."
          }
        ],
        "id": "CVE-2026-121727",
        "lastModified": "2026-11-03T23:17:36.043",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
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                "baseScore": 7.5,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "NONE",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                "version": "3.1"
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              "source": "disclosure@vulncheck.com",
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            }
          ],
          "cvssMetricV40": [
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                "Recovery": "NOT_DEFINED",
                "Safety": "NOT_DEFINED",
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                "attackVector": "NETWORK",
                "availabilityRequirement": "NOT_DEFINED",
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                "baseSeverity": "HIGH",
                "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:N/PR:N/UI:N/VC:N/VI:N/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",
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                "vulnerabilityResponseEffort": "NOT_DEFINED"
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        "references": [
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            "url": "https://github.com/jorisvink/kore"
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            "source": "disclosure@vulncheck.com",
            "url": "https://github.com/jorisvink/kore/blob/4.3.0-rc5/src/http.c#L934"
          },
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            "source": "disclosure@vulncheck.com",
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            "url": "https://www.vulncheck.com/advisories/kore-before-4.3.0-integer-underflow-memory-exhaustion-via-http-header-recv"
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    "redhat_vex": {
      "current_release_date": "2026-11-06T17:37:46+00:00",
      "cve": "CVE-2026-121727",
      "id": "CVE-2026-121727",
      "initial_release_date": "2026-11-03T22:55:33.948000+00:00",
      "product_status:known_not_affected": "1",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kore: kore: Denial of Service via integer underflow in HTTP request body handling",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-121727.json",
      "version": "3"
    }
  }
}



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