This PR resolves the vulnerabilities described in Issue #9
Version 4.17.15
Risk Change
Critical
High
Medium
Low
N/A
0
4
2
0
Version 4.18.1
Risk Change
Critical
High
Medium
Low
-100%
0 (--)
0 (-4)
0 (-2)
0 (--)
Mend ensures you have the greatest risk reduction ("Recommended Fix"-highlighted in green) by removing as many vulnerabilities as possible. Click to see how we calculate risk reduction.
Fixes a ReferenceError issue in lodash lodash-es lodash-amd and lodash.template when using the template and fromPairs functions from the modular builds. See #6167 (comment)
These defects were related to how lodash distributions are built from the main branch using https://github.com/lodash-archive/lodash-cli. When internal dependencies change inside lodash functions, equivalent updates need to be made to a mapping in the lodash-cli. (hey, it was ahead of its time once upon a time!). We know this, but we missed it in the last release. It's the kind of thing that passes in CI, but fails bc the build is not the same thing you tested.
There is no diff on main for this, but you can see the diffs for each of the npm packages on their respective branches:
_.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)
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:
mend-for-github-comBot
changed the title
Update dependency lodash to v4.17.23
Update dependency lodash to v4.18.1
Aug 10, 2026
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This PR contains the following updates:
This PR resolves the vulnerabilities described in Issue #9
Version 4.17.15
Mend ensures you have the greatest risk reduction ("Recommended Fix"-highlighted in green) by removing as many vulnerabilities as possible. Click to see how we calculate risk reduction.
Release Notes
lodash/lodash (lodash)v4.18.1
Compare Source
Bugs
Fixes a ReferenceError issue in lodash lodash-es lodash-amd and lodash.template when using the template and fromPairs functions from the modular builds. See #6167 (comment)
These defects were related to how lodash distributions are built from the main branch using https://github.com/lodash-archive/lodash-cli. When internal dependencies change inside lodash functions, equivalent updates need to be made to a mapping in the lodash-cli. (hey, it was ahead of its time once upon a time!). We know this, but we missed it in the last release. It's the kind of thing that passes in CI, but fails bc the build is not the same thing you tested.
There is no diff on main for this, but you can see the diffs for each of the npm packages on their respective branches:
v4.18.0
Compare Source
v4.18.0
Full Changelog: lodash/lodash@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
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:
v4.17.23
Compare Source
v4.17.21
Compare Source
v4.17.20
Compare Source
v4.17.16
Compare Source