[nealrichardson]

Two small dependency cleanups.

Changes

• KaTeX override. Mermaid 11.17.2 depends on katex ^0.16.47, which has GHSA-238p-pmpm-9mq7 (low: prototype pollution elsewhere on the page can turn on KaTeX's trust option). The fix is in 0.18.2, and no 0.16.x release has it. The root package.json now has "overrides": { "mermaid": { "katex": "^0.18.2" } }, which resolves to 0.18.10.
  • Why it's safe: Mermaid 12.2 moved to katex ^0.18.0, and its KaTeX code (renderKatexUnsanitized: dynamic import("katex"), then renderToString with MathML output by default) is identical to 11.17.2's. KaTeX's breaking changes don't apply here. 0.17 changed an internal __defineFunction API, and 0.18 prefixes KaTeX's CSS classes, which only matters for HTML output styled by KaTeX's stylesheet. We use MathML output and don't load that stylesheet.
  • When to remove it: once Mermaid is at 12.2 or later. npm overrides can't carry a comment, so this is recorded here.
  • This is scanner hygiene, not a security fix. It clears the runtime finding from npm audit, Dependabot and Snyk, so it doesn't sit open until Mermaid 12. The one place it changes code is the notebook renderer, where the advisory already couldn't do harm: the renderer shows Mermaid's SVG as an <img> data URL, so links, scripts and external resources in it are inert.
  • Not covered: the diagram preview's checked-in assets/www/diagram/mermaid.min.js is Mermaid's prebuilt bundle with KaTeX 0.16.47 compiled in, so no override or lockfile change reaches it. It's also the more exposed of the two, since diagram.js inserts the SVG with innerHTML (after Mermaid's default strict DOMPurify pass). Fixing it needs Mermaid 12, or bundling Mermaid for the preview ourselves. Scanners don't see that file.
• Drop which (and @types/which). It was used once, in activePythonInterpreter, to resolve a bare python name from the Python extension against PATH. A small local findOnPath helper now does that, following which@3's rules: PATHEXT on Windows, quoted PATH entries, executable files only. Names with a directory part are left as they are, as before. which 7 needs Node ≥22.22, newer than VS Code 1.101's extension host, so this also removes a reason for a Dependabot ignore (build: add Dependabot for npm dependencies #1198).

Verification

• package-lock.json diff: only which, @types/which, and katex 0.16.47 → 0.18.10 (with its CLI's commander 8 → 15, which isn't bundled). npm ls --all exits 0.
• npm audit --omit=dev: 2 low → 0.
• npm run build -- --force: 9/9. The notebook renderer's out/markdownit/katex-*.js chunk is 0.18.10.
• npm run lint -- --continue: 17/17, 0 errors, 17 warnings (unchanged). npm run test-packages: 13/13.
• Headless Chromium, with Mermaid 11.17.2 bundled the way our renderer bundles it (from mermaid.core.mjs, so it uses our KaTeX): a flowchart with $$x^2 + \frac{a}{b}$$ and $$\sqrt{\alpha}$$ labels and a sequence diagram with $$\sum_{i=1}^n i$$ render with <math> elements, no syntax error, and no console errors or warnings.
• findOnPath gives the same result as command -v for python3, python (absent), node, git and a missing name, on macOS. Not checked on Windows.

🤖 Generated with Claude Code

[posit-snyk-bot]

⚠️ Snyk checks are incomplete.

Status	Scan Engine	Critical	High	Medium	Low	Total (0)
⚠️	Open Source Security	0	0	0	0	See details
⚠️	Licenses	0	0	0	0	See details

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[juliasilge]

Thank you!