Security readout for executives and security teams
Plain-English summary
This issue concerns exceljs handling of worksheet cell values. If an application displays a worksheet in a browser, an unescaped cell value could run as cross-site scripting. The business risk is mainly to users viewing attacker-controlled spreadsheet content, not to back-end systems by default.
Executive priority
Treat this as a targeted web application risk. Prioritize remediation if customers, staff, or administrators view uploaded or externally supplied spreadsheets in a browser.
Technical view
CVE-2018-16459 is a CWE-79 XSS issue in exceljs. The provided description says exceljs before v1.6 allows an unescaped payload via cell value when a worksheet is displayed in a browser. The affected metadata is limited and inconsistent, so confirm version impact against vendor guidance.
Likely exposure
Exposure is likely where exceljs is used to render or display spreadsheet cell content in browser-facing workflows, especially with user-supplied workbook data. Server-only generation of trusted spreadsheets is lower concern based on the supplied evidence.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation evidence. Exploitation appears context-dependent: an attacker would need control over cell content that is later rendered in a victim’s browser.
Researcher notes
The bundle lists severity as unknown and provides no CVSS. The description says exceljs <v1.6, while affected metadata lists 1.6.0, so version boundaries require vendor confirmation before broad assertions.
Mitigation direction
- Check upstream exceljs guidance for the confirmed fixed version.
- Upgrade exceljs to a vendor-confirmed non-affected release.
- Avoid browser display of untrusted worksheet values until remediated.
- HTML-escape or sanitize cell values at the rendering boundary.
Validation and detection
- Inventory applications and lockfiles for exceljs usage.
- Identify routes that display worksheet data in browsers.
- Check whether displayed cell values can come from untrusted users.
- Confirm dependency version against the vendor advisory or HackerOne report.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2018-16459 mapping review
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Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://hackerone.com/reports/356809CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.