{
  "affected": [
    {
      "affectedData": [
        {
          "product": "excelize",
          "vendor": "qax-os",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 2.7.1, \u003c= 2.11.0"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Excelize is a Go language library for reading and writing Microsoft Excel spreadsheets. From 2.7.1 to 2.11.0, mergeCellsParser leaves the cached rectangle empty for an empty mergeCell ref and then passes that empty slice to cellInRange without a length check. GetCellValue reaches mergeCellsParser, which passes an empty rectangle derived from the mergeCell ref attribute into cellInRange. When a crafted worksheet contains an empty mergeCell ref and a non-streaming cell API reads the worksheet, cellInRange indexes four positions in an empty slice, allowing an attacker to panic on the first affected cell operation. No fixed version is available as of this review."
    }
  ],
  "id": "CVE-2026-107220",
  "lastModified": "2026-10-07T19:17:34.447",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 6.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 3.6,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-10-07T19:17:34.447",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/qax-os/excelize/commit/99903a3240e58a47ff28fb8e05a03bd9d496ec24"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/qax-os/excelize/pull/2379"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/qax-os/excelize/security/advisories/GHSA-g27h-8qhm-6pff"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-125"
        },
        {
          "lang": "en",
          "value": "CWE-129"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}

{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/xuri/excelize/v2"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.7.1"
            },
            {
              "fixed": "2.11.1-0.20260820023833-99903a3240e5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-107220"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-125",
      "CWE-129"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-07T20:23:17Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Summary\n\nA worksheet containing `\u003cmergeCell ref=\"\"/\u003e` makes `mergeCellsParser` leave the cached rectangle empty, and `cellInRange` then indexes that empty slice without a length check. Every non-streaming cell API panics with `index out of range [0] with length 0` on the first cell read after opening the file.\n\n### Where it is\n\n`cell.go`, `cellInRange`\n\n    func cellInRange(cell, ref []int) bool {\n    \treturn cell[0] \u003e= ref[0] \u0026\u0026 cell[0] \u003c= ref[2] \u0026\u0026 cell[1] \u003e= ref[1] \u0026\u0026 cell[1] \u003c= ref[3]\n    }\n\n`ref` is indexed at four positions with no bounds check.\n\nThe caller that can hand it an empty slice, `mergeCellsParser`\n\n    if ref := ws.MergeCells.Cells[i].Ref; len(ws.MergeCells.Cells[i].rect) == 0 \u0026\u0026 ref != \"\" {\n    \tif strings.Count(ref, \":\") != 1 {\n    \t\tref += \":\" + ref\n    \t}\n    \trect, err := rangeRefToCoordinates(ref)\n    \tif err != nil {\n    \t\treturn cell, err\n    \t}\n    \t_ = sortCoordinates(rect)\n    \tws.MergeCells.Cells[i].rect = rect\n    }\n    if cellInRange([]int{col, row}, ws.MergeCells.Cells[i].rect) {\n\nThe `ref != \"\"` condition means an empty `ref` skips the block that populates `rect`, so `rect` stays nil. The `cellInRange` call on the next line is unconditional and receives that nil slice.\n\n`Ref` comes straight from `xl/worksheets/sheetN.xml` through `encoding/xml`, so an empty string is entirely attacker-controlled.\n\n### Impact\n\nAny consumer that opens an untrusted workbook and reads a cell panics. The loop scans every merged cell, so any cell reference triggers it, not a specific one. Affected entry points include `GetCellValue`, `GetCellType`, `GetCellFormula`, `SetCellValue` and the in-cell branch of `GetPictures`. The streaming `Rows` and `GetRows` use the SAX path and do not go through this parser, and `GetMergeCells` routes through `Rect()` which errors cleanly, which is probably why this has not surfaced before.\n\nThere is no option or flag involved; opening the file succeeds and the panic fires on the first cell read. Unless the caller wraps the call in `recover()` it takes the process down.\n\nThis is a regression. Commit a34c81e (PR #1500, 2023-03-20) replaced `checkCellInRangeRef`, whose `len(rng) != 2` guard returned cleanly for an empty ref, with the cached-rect fast path above, and the guard did not come along. `git merge-base --is-ancestor` confirms that commit is an ancestor of v2.11.0, so released versions are affected as well as HEAD.\n\n### Proof of concept\n\nExecuted at HEAD.\n\nBuild a minimal xlsx whose `xl/worksheets/sheet1.xml` contains:\n\n    \u003cmergeCells count=\"1\"\u003e\u003cmergeCell ref=\"\"\u003e\u003c/mergeCell\u003e\u003c/mergeCells\u003e\n\nThen:\n\n    f, err := excelize.OpenReader(bytes.NewReader(data))\n    if err != nil { t.Fatal(err) }\n    _, _ = f.GetCellValue(\"Sheet1\", \"A1\")\n\nObserved, running against the repository at HEAD:\n\n    panic: runtime error: index out of range [0] with length 0\n      excelize.cellInRange           cell.go:1691\n      excelize.(*xlsxWorksheet).mergeCellsParser  cell.go:1660\n      excelize.(*File).getCellStringFunc          cell.go:1512\n      excelize.(*File).GetCellValue               cell.go:72\n\n`OpenReader` itself returns no error; the file is 1656 bytes. A1, B1 and A2 all reproduce it.\n\nFor context on how targeted this is, I ran a battery of 38 crafted files covering data validation, conditional formatting, cell and row references, number formats, cols, hyperlinks, dimension, shared strings and tables. Only the empty-ref merge cell panicked; everything else returned a clean error. The other parsing paths look well guarded.\n\n### Suggested fix\n\nSkip the entry when the rectangle is empty, before the range test:\n\n    if len(ws.MergeCells.Cells[i].rect) == 0 {\n    \tcontinue\n    }\n\nCredit goes to arpitjain099.",
  "id": "GHSA-g27h-8qhm-6pff",
  "modified": "2026-10-07T20:23:17Z",
  "published": "2026-10-07T20:23:17Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/qax-os/excelize/security/advisories/GHSA-g27h-8qhm-6pff"
    },
    {
      "type": "WEB",
      "url": "https://github.com/qax-os/excelize/pull/2379"
    },
    {
      "type": "WEB",
      "url": "https://github.com/qax-os/excelize/commit/99903a3240e58a47ff28fb8e05a03bd9d496ec24"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/qax-os/excelize"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Excelize: Panic in cellInRange on a worksheet with an empty mergeCell ref"
}