CVE Intelligence
Medium Injection

CVE-2026-2950 — lodash vulnerable to Prototype Pollution via array path bypass in `_.unset` and `_.omit`

The _.unset and _.omit functions in Lodash are vulnerable to prototype pollution. 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. The issue is patched from 4.18.0 to 4.18.1 depending on the package: lodash, lodash-es, and lodash-amd in 4.18.1, and the standalone lodash.unset and lodash.omit packages in 4.18.0.

Published Mar 31, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: openjs

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.4% (30-day exploitation probability)+5
  • Technical severity (medium)+3
  • Automatable exploitation (SSVC)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.38%
ahead of 30% of scored CVEs · Oct 14, 2026
Affects
Lodash
Lodash and 4 more
CVSS base
5.3
Medium · 4 source(s)
Prioritization reference: 6.5 provisional

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
Yes
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

  • Npm Lodash: fixed in version 4.18.0 — github.com (GitHub Security Advisories)
  • Npm Lodash.unset: fixed in version 4.18.0 — github.com (GitHub Security Advisories)
  • Npm Lodash-es: fixed in version 4.18.0 — github.com (GitHub Security Advisories)
  • Npm Lodash-amd: fixed in version 4.18.0 — github.com (GitHub Security Advisories)

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Lodash Lodash, Lodash Lodash-amd, Lodash Lodash-es…).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. Apply the fixed version or the patch documented under Remediation.
  4. Search available logs for exploit probes matching the vulnerability class (injection), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Lodash Lodash ≥ 4.0.0 and < 4.17.23 Vulnerable NIST National Vulnerability Database
Lodash Lodash ≥ 4.17.23 and < 4.18.1 Vulnerable CVE Program (cve.org) e CISA ADP
Lodash Lodash-amd ≥ 4.0.0 and < 4.17.23 Vulnerable NIST National Vulnerability Database
Lodash Lodash-amd ≥ 4.17.23 and < 4.18.1 Vulnerable CVE Program (cve.org) e CISA ADP
Lodash Lodash-es ≥ 4.0.0 and < 4.17.23 Vulnerable NIST National Vulnerability Database
Lodash Lodash-es ≥ 4.17.23 and < 4.18.1 Vulnerable CVE Program (cve.org) e CISA ADP
Lodash Lodash.omit < 4.18.0 Vulnerable CVE Program (cve.org) e CISA ADP
Lodash Lodash.unset ≥ 4.0.0 Vulnerable NIST National Vulnerability Database
Lodash Lodash.unset < 4.18.0 Vulnerable CVE Program (cve.org) e CISA ADP
Npm Lodash ≤ 4.17.23 Vulnerable GitHub Security Advisories
Npm Lodash-amd ≤ 4.17.23 Vulnerable GitHub Security Advisories
Npm Lodash-es ≤ 4.17.23 Vulnerable GitHub Security Advisories
Npm Lodash.unset ≥ 4.0.0 and < 4.18.0 Vulnerable GitHub Security Advisories

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
6.5 CVSS 3.1 Medium 3.9 2.5 ce714d77-add3-4f53-aff5-83d477b104bb via NIST National Vulnerability Database
6.5 CVSS 3.1 Medium — — GitHub, Inc. via GitHub Security Advisories
6.5 CVSS 3.1 Medium — — openjs via CVE Program (cve.org) e CISA ADP
5.3 CVSS 3.1 Medium 3.9 1.4 nvd@nist.gov via NIST National Vulnerability Database
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N (score shown at the top: nvd@nist.gov)
Scoring entities (NIST, CNA, ADP) score independently; each score is shown with its origin. For prioritization we use 6.5 (ce714d77-add3-4f53-aff5-83d477b104bb via NIST National Vulnerability Database) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-1321 · Prototype Pollution

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 0.38%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Look for parameters with command/query metacharacters and unexpected child processes of the service.
web/proxy/WAF logsnetwork IDS/IPSapplication logsendpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

  • 2026
  • Fix documented
    Oct 15, 2026 · GitHub Security Advisories
  • Affected products added · npm/lodash, npm/lodash-es, npm/lodash-amd, npm/lodash.unset
    Oct 15, 2026 · GitHub Security Advisories
  • Affected products removed · 4
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • Affected products added · lodash/lodash, lodash/lodash-es, lodash/lodash-amd, lodash/lodash.unset, lodash/lodash.omit
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • Source status changed · Analyzed → Modified
    Oct 15, 2026 · NIST National Vulnerability Database
  • Affected products added · lodash/lodash, lodash/lodash-es, lodash/lodash-amd, lodash/lodash.unset
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 13, 2026
  • CVSS changed · 5.3
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Analyzed
    Oct 13, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVE published
    Mar 31, 2026 · openjs

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 15, 2026 – Oct 15, 2026
  • 2× Official description updated · Oct 13, 2026 – Oct 15, 2026

References

5 on the record

Elsewhere on this site

Lodash
every CVE for this vendor
Injection
same class
CWE-1321
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-4800 lodash vulnerable to Code Injection via `_.template` imports key names Mar 31, 2026
  • CVE-2025-13465 Prototype Pollution Vulnerability in Lodash _.unset and _.omit functions Jan 21, 2026
  • CVE-2021-23337 Command Injection Feb 15, 2021
  • CVE-2020-28500 Regular Expression Denial of Service (ReDoS) Feb 15, 2021

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-2950 is "lodash vulnerable to Prototype Pollution via array path bypass in `_.unset` and `_.omit`", rated Medium. It affects Lodash (Lodash); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.3 describes technical severity. EPSS 0.38% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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