CVE-2026-78207: falha crítica em exceljs
exceljs through 4.4.0 Prototype Pollution via deepMerge Reached From Note Serialization
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Aviso por e-mail quando ela entrar no KEV, ganhar PoC pública ou subir de nota.
28Vexday Risk Score
Sem sinal de exploração. Nenhum artefato público de exploração conhecido até agora.
ssvc Trackcvss 9.3epss 0.6%
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.prototype and affecting all plain objects created in the process.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N
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Referências
https://github.com/exceljs/exceljshttps://github.com/exceljs/exceljs/blob/v4.4.0/lib/utils/under-dash.js#L155-L181https://github.com/mateocallec/exceljs-hardened/security/advisories/GHSA-qwr4-7h29-chpfhttps://www.vulncheck.com/advisories/exceljs-through-prototype-pollution-via-deepmerge-reached-from-note-serialization