CVE•Published 2026-08-24•Modified 2026-08-31•1 article on news•4 live references•NVD data
CVE-2026-78207
Vulnerability data via NVD (ingested)
CVSS v3.1
9.4
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L
EPSS percentile
37
Exploit Prediction Scoring System · top 63% of all CVEs
Weaknesses (CWE)
Description
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.
Timeline
Published 2026-08-24
Modified 2026-08-31
External references
Search for exposed instances
Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).
More intel sources (5)
Shodan report
vuln:CVE-2026-78207Country / ASN / product breakdown for the vuln query.
Censys
vulnerabilities.cve_id: CVE-2026-78207Censys host search filtered to this CVE id.
grep.app
CVE-2026-78207Public source-code mentions — fast PoC discovery.
GitHub code
CVE-2026-78207GitHub code search for direct mentions.
Google dork
"CVE-2026-78207" exploit -site:nvd.nist.govWrite-ups and news, NVD excluded.
Known PoCs on GitHub
No public proof-of-concept repositories found for CVE-2026-78207 on GitHub.