FKIE_CVE-2026-6103

Vulnerability from fkie_nvd - Published: 2026-09-25 21:17 - Updated: 2026-09-25 21:17
Severity
4.3 (Medium) - CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
Summary
phar_tar_number() parses the octal size field of a TAR header into a uint32_t with no overflow check. The field is 11 octal digits wide and holds values up to 0x1FFFFFFFF, so a size above 0xFFFFFFFF silently wraps. The parser then skips the wrong number of data blocks and interprets attacker-controlled file content as the next TAR header, which lets a crafted archive inject entries that PharData reports and extracts as if they were genuine.
References
security@php.nethttps://github.com/php/php-src/security/advisories/GHSA-j3wh-g957-2m85
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/php/php-src/security/advisories/GHSA-j3wh-g957-2m85
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "PHP",
          "vendor": "PHP Group",
          "versions": [
            {
              "lessThan": "8.2.34",
              "status": "affected",
              "version": "8.2.*",
              "versionType": "semver"
            },
            {
              "lessThan": "8.3.35",
              "status": "affected",
              "version": "8.3.*",
              "versionType": "semver"
            },
            {
              "lessThan": "8.4.26",
              "status": "affected",
              "version": "8.4.*",
              "versionType": "semver"
            },
            {
              "lessThan": "8.5.11",
              "status": "affected",
              "version": "8.5.*",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "security@php.net"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "phar_tar_number() parses the octal size field of a TAR header into a uint32_t with no overflow check. The field is 11 octal digits wide and holds values up to 0x1FFFFFFFF, so a size above 0xFFFFFFFF silently wraps. The parser then skips the wrong number of data blocks and interprets attacker-controlled file content as the next TAR header, which lets a crafted archive inject entries that PharData reports and extracts as if they were genuine."
    }
  ],
  "id": "CVE-2026-6103",
  "lastModified": "2026-09-25T21:17:23.790",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "NONE",
          "baseScore": 4.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.5,
        "impactScore": 1.4,
        "source": "security@php.net",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-6103",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-09-25T20:41:05.626504Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-09-25T21:17:23.790",
  "references": [
    {
      "source": "security@php.net",
      "url": "https://github.com/php/php-src/security/advisories/GHSA-j3wh-g957-2m85"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/php/php-src/security/advisories/GHSA-j3wh-g957-2m85"
    }
  ],
  "sourceIdentifier": "security@php.net",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-190"
        }
      ],
      "source": "security@php.net",
      "type": "Secondary"
    }
  ]
}



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