AIKIDO-2026-709565
fonttools is vulnerable to Cross-Site Scripting (XSS)
59
Medium Risk
This Affects:
fonttoolsTL;DR
The fontTools.varLib.interpolatable HTML report embeds glyph names directly into the generated HTML document. Glyph names read from an input font are written into <h1> headings without escaping, so a font whose glyph names contain HTML or script markup injects that markup into the report. Opening the report in a browser then renders the injected markup. The fix escapes glyph names with html.escape before writing them into the report.
Who does this affect?
You are affected if you are using a version that falls within the vulnerable range and you generate an interpolatable HTML report from untrusted fonts and open that report in a browser.
Background info
fonttools is vulnerable to Cross-Site Scripting (XSS) in versions 4.46.0 - 4.64.0.
How to fix this
Upgrade the fonttools library to the patch version.
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SOC 2Compliant
ISO 27001CompliantISO 42001Compliant
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