CVE-2026-2950 — lodash
MEDIUMCVE-2026-2950 is a medium-severity (CVSS 6.5) CWE-1321 vulnerability in lodash. A fix is available for lodash — see the affected versions and patch details below.
lodash vulnerable to Prototype Pollution via array path bypass in `_.unset` and `_.omit`
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-2950.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-2950 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
lodashnpmlodash-esnpmlodash-amdnpmDescription
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | lodash | all versions | 4.18.0npm install lodash@4.18.0 |
| 📦npm | lodash-es | all versions | 4.18.0npm install lodash-es@4.18.0 |
| 📦npm | lodash-amd | all versions | 4.18.0npm install lodash-amd@4.18.0 |
| 📦npm | lodash.unset | ≥ 4.0.0&&< 4.18.0 | 4.18.0npm install lodash.unset@4.18.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for lodash, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-2950 can be triaged on real exposure rather than presence alone.
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.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Developer Hub 1.10 | rhdh/rhdh-hub-rhel9:1780930740 | RHSA-2026:24841 |
| Red Hat Hardened Images | nodejs25-main-25.9.0-1.1.hum1 | RHSA-2026:7378 |
| Red Hat Hardened Images | yarnpkg-main-1.22.22-18.1.hum1 | RHSA-2026:7655 |
| Red Hat Hardened Images | nodejs20-main-20.20.2-1.hum1 | RHSA-2026:9455 |
Frequently Asked Questions
Is CVE-2026-2950 in your dependencies?
O3 Security finds CVE-2026-2950 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.