CVE-2026-115569: Fallow: Jest and Vitest `projects` entries let an analyzed repository make Fallow read files outside the project root

Severity: low (CVSS 3.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-23 · updated 2026-10-30
Weakness: CWE-22

Description

Fallow is a codebase intelligence tool for TypeScript and JavaScript. From 2.68.0 until 3.34.0, Fallow follows attacker-controlled Jest projects paths outside the project root through absolute paths, parent segments, dot-prefixed wildcard globs, or symlinks. In version 3.33.1, the same behavior also affects Vitest test.projects paths, Vitest inline-project extends paths, and symlinked script --config paths. Fallow parses the outside files as test-runner configuration and uses them to credit dependencies, setup files, and JSX import sources, which can change unused dependency and unused file findings in CI or agent analysis. The outside file contents are not printed or sent over the network. This issue is fixed in version 3.34.0.

Affected products

@fallow-cli fallow-node: from 2.68.0, < 3.34.0
fallow-rs fallow: from 2.68.0, < 3.34.0
fallow-rs fallow-cli: from 2.68.0, < 3.34.0
fallow-rs fallow-core: from 2.68.0, < 3.34.0

References

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