Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
lodash vulnerable to Code Injection via `_.template` imports key names
AV AC PR UI S C I A CVSS EPSS %ile KEV
N L N N U H H H 9.8 .0262 84.9 —
AFFECTED
Product Versions Fixed
lodash 4.0.0 – 4.18.0
lodash-es 4.0.0 – 4.18.0
lodash-amd 4.0.0 – 4.18.0
lodash.template 4.0.0 – 4.18.0
TIMELINE
Mar 25 Reserved by openjs
Mar 31 Published (CNA: openjs)
Aug 24 RESCORED — CVE-2026-4800 (lodash). CVSS 8.1 → 9.8 (NVD).
Description
Impact:
The fix for CVE-2021-23337 (https://github.com/advisories/GHSA-35jh-r3h4-6jhm) 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.
Workarounds:
Do not pass untrusted input as key names in options.imports. Only use developer-controlled, static key names.
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-4800 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.
