How severe is CVE-2026-2950?

CVE-2026-2950 has a CVSS score of 6.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2026-2950?

CVE-2026-2950 affects the following packages: lodash (npm), lodash-es (npm), lodash-amd (npm), lodash.unset (npm). Ecosystems affected: npm.

How do I fix CVE-2026-2950?

Update lodash to 4.18.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-2950 is resolved across your whole dependency graph.

How do I detect CVE-2026-2950 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for lodash. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2026-2950 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-2950?

O3 pinpoints whether CVE-2026-2950 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2026-2950 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-2950 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What type of vulnerability is CVE-2026-2950?

CVE-2026-2950 is classified as CWE-1321 (CWE-1321). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-2950 published, and has it been updated?

CVE-2026-2950 was published on March 31, 2026 and was last updated on July 27, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

CVE-2026-2950

MEDIUM

CVE-2026-2950 is a medium-severity (CVSS 6.5) CWE-1321 vulnerability in lodash. O3 Security confirms whether CVE-2026-2950 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

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

Also known asCVE-2025-13465 GHSA-f23m-r3pf-42rh GHSA-xxjr-mmjv-4gpg

Published

Mar 31, 2026

Updated

Jul 27, 2026

Affected

4 pkgs

Patched

4 / 4

Exploits

None indexed

Blast Radius

4 pkgs affected

Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.

lodashnpm

166.5Mdownloads / week

lodash-esnpm

42.8Mdownloads / week

lodash-amdnpm

15Kdownloads / week

Description

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: https://github.com/lodash/lodash/security/advisories/GHSA-xxjr-mmjv-4gpg) 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.

Affected Packages

4 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`lodash`	all versions	4.18.0
📦npm	`lodash-es`	all versions	4.18.0
📦npm	`lodash-amd`	all versions	4.18.0
📦npm	`lodash.unset`	≥ 4.0.0&&< 4.18.0	4.18.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for lodash. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update lodash to 4.18.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-2950 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-2950 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2026-2950. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

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: https://github.com/lodash/lodash/security/advisories/GHSA-xxjr-mmjv-4gpg) 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 pa

O3 Security · Impact-Aware SCA

Is CVE-2026-2950 in your dependencies?

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