🚨 [security] Update lodash 4.17.21 → 4.18.1 (minor)

[depfu]

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🚨 Your current dependencies have known security vulnerabilities 🚨

This dependency update fixes known security vulnerabilities. Please see the details below and assess their impact carefully. We recommend to merge and deploy this as soon as possible!

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Here is everything you need to know about this update. Please take a good look at what changed and the test results before merging this pull request.

What changed?

✳️ lodash (4.17.21 → 4.18.1) · Repo · Changelog

Security Advisories 🚨

🚨 lodash vulnerable to Prototype Pollution via array path bypass in `_.unset` and `_.omit`

Impact

Lodash versions 4.17.23 and earlier are vulnerable to prototype pollution in the _.unset and _.omit functions. The fix for CVE-2025-13465 only guards against string key members, so an attacker can bypass the check by passing array-wrapped path segments. This allows deletion of properties from built-in prototypes such as Object.prototype, Number.prototype, and String.prototype.

The issue permits deletion of prototype properties but does not allow overwriting their original behavior.

Patches

This issue is patched in 4.18.0.

Workarounds

None. Upgrade to the patched version.

🚨 lodash vulnerable to Code Injection via `_.template` imports key names

Impact

The fix for CVE-2021-23337 added validation for the variable option in _.template but did not apply the same validation to options.imports key names. Both paths flow into the same Function() constructor sink.

When an application passes untrusted input as options.imports key names, an attacker can inject default-parameter expressions that execute arbitrary code at template compilation time.

Additionally, _.template uses assignInWith to merge imports, which enumerates inherited properties via for..in. If Object.prototype has been polluted by any other vector, the polluted keys are copied into the imports object and passed to Function().

Patches

Users should upgrade to version 4.18.0.

The fix applies two changes:

1. Validate importsKeys against the existing reForbiddenIdentifierChars regex (same check already used for the variable option)
2. Replace assignInWith with assignWith when merging imports, so only own properties are enumerated

Workarounds

Do not pass untrusted input as key names in options.imports. Only use developer-controlled, static key names.

🚨 Lodash has Prototype Pollution Vulnerability in `_.unset` and `_.omit` functions

Impact

Lodash versions 4.0.0 through 4.17.22 are vulnerable to prototype pollution in the _.unset and _.omit functions. An attacker can pass crafted paths which cause Lodash to delete methods from global prototypes.

The issue permits deletion of properties but does not allow overwriting their original behavior.

Patches

This issue is patched on 4.17.23.

Release Notes

4.18.0

v4.18.0

Full Changelog: 4.17.23...4.18.0

Security

_.unset / _.omit: Fixed prototype pollution via constructor/prototype path traversal (GHSA-f23m-r3pf-42rh, fe8d32e). Previously, array-wrapped path segments and primitive roots could bypass the existing guards, allowing deletion of properties from built-in prototypes. Now constructor and prototype are blocked unconditionally as non-terminal path keys, matching baseSet. Calls that previously returned true and deleted the property now return false and leave the target untouched.

_.template: Fixed code injection via imports keys (GHSA-r5fr-rjxr-66jc, CVE-2026-4800, 879aaa9). Fixes an incomplete patch for CVE-2021-23337. The variable option was validated against reForbiddenIdentifierChars but importsKeys was left unguarded, allowing code injection via the same Function() constructor sink. imports keys containing forbidden identifier characters now throw "Invalid imports option passed into _.template".

Docs

• Add security notice for _.template in threat model and API docs (#6099)
• Document lower > upper behavior in _.random (#6115)
• Fix quotes in _.compact jsdoc (#6090)

lodash.* modular packages

Diff

We have also regenerated and published a select number of the lodash.* modular packages.

These modular packages had fallen out of sync significantly from the minor/patch updates to lodash. Specifically, we have brought the following packages up to parity w/ the latest lodash release because they have had CVEs on them in the past:

• lodash.orderby
• lodash.tonumber
• lodash.trim
• lodash.trimend
• lodash.sortedindexby
• lodash.zipobjectdeep
• lodash.unset
• lodash.omit
• lodash.template

Does any of this look wrong? Please let us know.

Commits

See the full diff on Github. The new version differs by 34 commits:

• release(patch): bump main to 4.18.1 (#6177)
• chore: prune stale advisory refs (#6170)
• docs: remove n_ Node.js < 6 REPL note from README (#6165)
• release(minor): bump to 4.18.0 (#6161)
• fix: broken tests for _.template 879aaa9
• fix: linting issues
• fix: validate imports keys in _.template
• fix: block prototype pollution in baseUnset via constructor/prototype traversal
• refactor(fromPairs): use baseAssignValue for consistent assignment (#6153)
• ci: add dist sync validation workflow (#6137)
• docs(random): document lower > upper case (#6115)
• docs: add security notice for `_.template` in threat model and API docs (#6099)
• doc: fix quotes in compact jsdoc (#6090)
• Bump main to v4.17.23 (#6088)
• fix: setCacheHas JSDoc return type should be boolean (#6071)
• jsdoc: Add -0 and BigInt zeros to _.compact falsey values list (#6062)
• Prevent prototype pollution on baseUnset function
• doc: fix autoLink function, conversion of source links (#6056)
• chore: remove `yarn.lock` file (#6053)
• ci: remove legacy configuration files (#6052)
• feat: add renovate setup (#6039)
• ci: add pipeline for Bun (#6023)
• docs: update links related to Open JS Foundation (#5968)
• Add contributors section to README
• fix: linting issues (#6033)
• Add CI pipeline for Node (#6022)
• security: Include a threat model (#6026)
• feat: add CodeQL (#6032)
• docs: add an IRP (#6028)
• feat: add scorecard reporting (#6030)
• docs: add security escalation policy (#6025)
• ci: add pipeline to run tests on browsers (#6021)
• ci: add ci pipeline for documentation (#6020)
• add security.md from afcd5bc (#5946)

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