ExcelJS through 4.4.0 contains a prototype pollution vulnerability that allows attackers to add numeric keys to Object.prototype through a crafted defined name referencing a proto sheet. Attackers can supply an xlsx whose xl/workbook.xml definedName range targets proto, causing C...
Product
npm exceljs vulnerabilities
18 published CVES affecting npm exceljs, from public sources (CVE.org, NVD, CISA KEV, FIRST EPSS, OSV).
- Total
- 18
- Critical
- 1
- High
- 13
- Medium
- 3
- Low
- 1
- Unscored
- 0
- CISA KEV
- 0
Latest npm exceljs CVEs
Newest publication first
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MediumCVSS 6.3
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CVE-2026-128338 ExcelJS through 4.4.0 Memory Exhaustion via Unbounded Worksheet Column Range
PublishedHighCVSS 8.7exceljs through 4.4.0 contains a memory exhaustion vulnerability that allows attackers to crash applications by supplying a worksheet col element with an unbounded max attribute. Attackers can craft a small workbook with a huge max value, causing xlsx.load() to allocate hundreds...
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CVE-2026-128337 ExcelJS through 4.4.0 Prototype Pollution via x14 Conditional Formatting Rule ID
PublishedHighCVSS 8.3ExcelJS through 4.4.0 contains a prototype pollution vulnerability in mergeConditionalFormattings that allows attackers to modify Object.prototype by supplying an x14:cfRule id of proto. Attackers can craft an xlsx file that, when loaded with xlsx.load(), sets properties such as...
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HighCVSS 8.7
ExcelJS through 4.4.0 contains a memory exhaustion vulnerability in Worksheet._parseMergeCells that allows attackers to crash applications by supplying unbounded mergeCell ranges. Attackers can craft a small workbook with a mergeCell ref like A1:XFD1048576, causing xlsx.load() to...
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CVE-2026-128341 ExcelJS through 4.4.0 Denial of Service via Oversized Data Validation sqref
PublishedHighCVSS 8.7ExcelJS through 4.4.0 contains a resource exhaustion vulnerability in data-validations-xform.js that allows attackers to exhaust CPU and memory by supplying unbounded sqref ranges. Attackers can provide a small crafted workbook with a sqref of A1:XFD1048576 to make xlsx.load() it...
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HighCVSS 8.7
ExcelJS through 4.4.0 contains a memory exhaustion vulnerability that allows attackers to crash applications by supplying a workbook with an oversized defined-name range. DefinedNames.addEx expands ranges such as S!$A$1:$XFD$1048576 from xl/workbook.xml cell by cell, causing an u...
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HighCVSS 8.7
ExcelJS through 4.4.0 contains a denial of service vulnerability that allows attackers to block the event loop by supplying an unbounded sheetId in xl/workbook.xml. Attackers can provide a workbook with a huge sheetId, making the sparse worksheet array walk stall worksheets, getW...
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HighCVSS 8.7
ExcelJS through 4.4.0 contains a memory exhaustion vulnerability that allows attackers to crash applications by supplying a workbook with an unbounded image anchor column in the drawing part. Attackers can set an anchor column such as 300000000 in xl/drawings/drawing1.xml so read...
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HighCVSS 8.7
exceljs through 4.4.0 contains a denial of service vulnerability that allows attackers to block the event loop by supplying unbounded row r attributes parsed in row-xform.js. Attackers can craft an XLSX file with a row numbered far beyond Excel's limit, making getSheetValues(), w...
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MediumCVSS 6.9
ExcelJS through 4.4.0 contains a regular expression denial of service vulnerability in slideFormula in lib/utils/shared-formula.js when translating shared formulas to child cells. Attackers can supply a crafted spreadsheet with very long master formulas, such as runs of hyphens,...
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CVE-2026-128347 ExcelJS through 4.4.0 Arbitrary File Read via WorkbookWriter addImage Filename
PublishedHighCVSS 8.7ExcelJS through 4.4.0 contains an arbitrary file read vulnerability in the streaming WorkbookWriter that allows attackers to read local files by supplying crafted image filenames to addImage. Attackers can inject ../ path segments into user-controlled image paths, causing addMedi...
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HighCVSS 8.7
ExcelJS through 4.4.0 contains a resource leak vulnerability in the streaming WorkbookReader.parse that leaves temporary files and open descriptors when sheet parsing fails or iteration stops early. Attackers can repeatedly upload malformed multi-sheet workbooks with worksheets p...
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LowCVSS 2.3
ExcelJS through 4.4.0 contains a formula injection vulnerability in the totals row formula getter in lib/doc/table.js that fails to escape [, ], # and ' characters in structured reference column names. Attackers can supply column names containing ] via untrusted input like import...
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HighCVSS 8.4 EPSS 0.41%
exceljs through 4.4.0 fails to neutralize leading equals, plus, minus, or at signs in cell values written to CSV output. Attackers who can influence exported cell values can inject formulas that execute when the CSV file is opened in a spreadsheet application, potentially exfiltr...
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CriticalCVSS 9.3 EPSS 0.60%
exceljs through 4.4.0 contains a prototype pollution vulnerability in the deepMerge helper that fails to reject proto, constructor, or prototype keys when merging note objects. Attackers can assign parsed JSON with a malicious proto property to cell notes, modifying Object.protot...
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HighCVSS 8.7 EPSS 0.51%
exceljs through 4.4.0 contains a path traversal vulnerability in the Workbook.addImage() function that fails to validate file paths. Attackers can supply arbitrary file paths to read any file accessible to the Node.js process and embed it in the generated workbook.
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HighCVSS 8.7 EPSS 0.63%
exceljs through 4.4.0 decompresses all entries from supplied xlsx archives into memory without limits on entry size, total size, or compression ratio. Attackers can upload highly compressed workbooks that expand to gigabytes in memory, exhausting available resources and causing d...
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MediumCVSS 6.1 EPSS 0.76%
An unescaped payload in exceljs <v1.6 allows a possible XSS via cell value when worksheet is displayed in browser.
Sources: CVE.org, NVD, CISA KEV, FIRST EPSS, OSV and public exploit-reference metadata. Product matching comes from the published CVE records. A proof-of-concept means public code exists; it is not evidence of exploitation.