# CVE-2026-78208: exceljs through 4.4.0 Path Traversal via Unvalidated addImage filename

Status: published. Published: 2026-08-24. Updated: 2026-11-08.

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.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- exceljs / exceljs (exceljs): ≥ 0; ≤ 4.4.0 (affected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 8.7 (high); CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N; source: CNA: VulnCheck

- CVSS 3.1: 7.5 (high); CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N; source: CNA: VulnCheck

- CISA KEV: No listing in collected sources

- EPSS: 0.51% as of 2026-11-08; percentile 43.69%

- SSVC: exploitation none; automatable yes; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-73

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/exceljs/exceljs (CNA: VulnCheck; product)

- https://github.com/mateocallec/exceljs-hardened/security/advisories/GHSA-m8mg-8574-gm3m (CNA: VulnCheck; third-party-advisory, vendor-advisory)

- https://github.com/exceljs/exceljs/blob/v4.4.0/lib/doc/workbook.js#L142-L147 (CNA: VulnCheck; technical-description)

- https://github.com/exceljs/exceljs/blob/v4.4.0/lib/xlsx/xlsx.js#L421-L429 (CNA: VulnCheck; technical-description)

- https://www.vulncheck.com/advisories/exceljs-through-path-traversal-via-unvalidated-addimage-filename (CNA: VulnCheck; third-party-advisory)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-78208; retrieved 2026-11-08; source updated 2026-11-08

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-78208; retrieved 2026-11-08; source updated Not reported

Revision: 3bdd928df9e82c09b440ebb44dd2e6d53057b2ece3edf1af0f04bfeea84e15f1

Canonical: https://y2.dev/cve/CVE-2026-78208

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.