GHSA-3cpv-r8x3-29fpCriticalCVSS 9.4
exceljs-hardened before 5.0.0 contains a prototype pollution vulnerability in the deepMerge...
🔗 CVE IDs covered (1)
📋 Description
exceljs-hardened before 5.0.0 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.prototype and affecting all plain objects created in the process.
🔗 References (6)
- https://github.com/mateocallec/exceljs-hardened/security/advisories/GHSA-qwr4-7h29-chpf
- https://nvd.nist.gov/vuln/detail/CVE-2026-78207
- https://github.com/exceljs/exceljs
- https://github.com/exceljs/exceljs/blob/v4.4.0/lib/utils/under-dash.js#L155-L181
- https://www.vulncheck.com/advisories/exceljs-through-prototype-pollution-via-deepmerge-reached-from-note-serialization
- https://github.com/advisories/GHSA-3cpv-r8x3-29fp