CVE-2026-55480 (GCVE-0-2026-55480)

Vulnerability from cvelistv5 – Published: 2026-10-15 17:09 – Updated: 2026-10-15 17:09
VLAI
Title
CUPS copy_model() creates a predictable PPD tempfile without O_EXCL/O_NOFOLLOW (symlink TOCTOU, lp → root)
Summary
OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. Prior to 2.4.20, copy_model() in scheduler/ipp.c creates a predictable TempDir/<connection-number>.ppd path in an lp-group-writable directory and opens it as root without O_EXCL or O_NOFOLLOW. Exploitation requires an lp-group process able to write that directory to predict the connection-derived name and plant a symlink before the root open, while a privileged add-printer or modify-printer operation using a model PPD triggers copy_model(). The reporter treats an existing lp foothold and the privileged operation as distinct prerequisites, while the maintainer assesses high privileges because installing the relevant filter or administering the printer requires root or print-administrator access. If the race succeeds, the root scheduler follows the symlink and truncates or overwrites a root-writable target with generated PPD data, compromising file integrity or availability. This issue is fixed in version 2.4.20.
Severity
5.7 (Medium)
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:H
CWE
  • CWE-59 - Improper Link Resolution Before File Access ('Link Following')
  • CWE-377 - Insecure Temporary File
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7712 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
OpenPrinting cups Affected: < 2.4.20
guessed Create a notification for this product.
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "cups",
          "vendor": "OpenPrinting",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.4.20"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. Prior to 2.4.20, copy_model() in scheduler/ipp.c creates a predictable TempDir/\u003cconnection-number\u003e.ppd path in an lp-group-writable directory and opens it as root without O_EXCL or O_NOFOLLOW. Exploitation requires an lp-group process able to write that directory to predict the connection-derived name and plant a symlink before the root open, while a privileged add-printer or modify-printer operation using a model PPD triggers copy_model(). The reporter treats an existing lp foothold and the privileged operation as distinct prerequisites, while the maintainer assesses high privileges because installing the relevant filter or administering the printer requires root or print-administrator access. If the race succeeds, the root scheduler follows the symlink and truncates or overwrites a root-writable target with generated PPD data, compromising file integrity or availability. This issue is fixed in version 2.4.20."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 5.7,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "HIGH",
            "privilegesRequired": "HIGH",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-59",
              "description": "CWE-59: Improper Link Resolution Before File Access (\u0027Link Following\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-377",
              "description": "CWE-377: Insecure Temporary File",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-15T17:09:33.878Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/OpenPrinting/cups/security/advisories/GHSA-jj94-x3qh-ffp9",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/OpenPrinting/cups/security/advisories/GHSA-jj94-x3qh-ffp9"
        },
        {
          "name": "https://github.com/OpenPrinting/cups/commit/98adfd855950e806508f961d5438ad32e26aac62",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/OpenPrinting/cups/commit/98adfd855950e806508f961d5438ad32e26aac62"
        },
        {
          "name": "https://github.com/OpenPrinting/cups/commit/f6a11dae0f0f3b748fbca931e237be03ffe8e48e",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/OpenPrinting/cups/commit/f6a11dae0f0f3b748fbca931e237be03ffe8e48e"
        },
        {
          "name": "https://github.com/OpenPrinting/cups/releases/tag/v2.4.20",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/OpenPrinting/cups/releases/tag/v2.4.20"
        }
      ],
      "source": {
        "advisory": "GHSA-jj94-x3qh-ffp9",
        "discovery": "UNKNOWN"
      },
      "title": "CUPS copy_model() creates a predictable PPD tempfile without O_EXCL/O_NOFOLLOW (symlink TOCTOU, lp \u2192 root)"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-55480",
    "datePublished": "2026-10-15T17:09:33.878Z",
    "dateReserved": "2026-06-16T22:28:27.061Z",
    "dateUpdated": "2026-10-15T17:09:33.878Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "cups",
                "vendor": "OpenPrinting",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003c 2.4.20"
                  }
                ]
              }
            ],
            "source": "security-advisories@github.com"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. Prior to 2.4.20, copy_model() in scheduler/ipp.c creates a predictable TempDir/\u003cconnection-number\u003e.ppd path in an lp-group-writable directory and opens it as root without O_EXCL or O_NOFOLLOW. Exploitation requires an lp-group process able to write that directory to predict the connection-derived name and plant a symlink before the root open, while a privileged add-printer or modify-printer operation using a model PPD triggers copy_model(). The reporter treats an existing lp foothold and the privileged operation as distinct prerequisites, while the maintainer assesses high privileges because installing the relevant filter or administering the printer requires root or print-administrator access. If the race succeeds, the root scheduler follows the symlink and truncates or overwrites a root-writable target with generated PPD data, compromising file integrity or availability. This issue is fixed in version 2.4.20."
          }
        ],
        "id": "CVE-2026-55480",
        "lastModified": "2026-10-15T18:17:27.987",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "HIGH",
                "attackVector": "LOCAL",
                "availabilityImpact": "HIGH",
                "baseScore": 5.7,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "NONE",
                "integrityImpact": "HIGH",
                "privilegesRequired": "HIGH",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 0.5,
              "impactScore": 5.2,
              "source": "security-advisories@github.com",
              "type": "Secondary"
            }
          ]
        },
        "published": "2026-10-15T18:17:27.987",
        "references": [
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/OpenPrinting/cups/commit/98adfd855950e806508f961d5438ad32e26aac62"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/OpenPrinting/cups/commit/f6a11dae0f0f3b748fbca931e237be03ffe8e48e"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/OpenPrinting/cups/releases/tag/v2.4.20"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/OpenPrinting/cups/security/advisories/GHSA-jj94-x3qh-ffp9"
          }
        ],
        "sourceIdentifier": "security-advisories@github.com",
        "vulnStatus": "Received",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-59"
              },
              {
                "lang": "en",
                "value": "CWE-377"
              }
            ],
            "source": "security-advisories@github.com",
            "type": "Primary"
          }
        ]
      }
    }
  }
}



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