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CVE-2026-93753

CVE-2026-93753 · deepmerge through 4.3.1 Prototype Poisoning via mergeObject

This page contains facts from public vulnerability sources. Check the original advisory before updating.

deepmerge through 4.3.1 contains a prototype poisoning vulnerability in the mergeObject() function that fails to properly validate keys being written to target objects. Attackers can supply malicious source objects in merge operations to inject attacker-controlled properties into the returned object's prototype, causing applications to inherit unintended values when accessing properties without own-property checks.

CVSS 8.7 · High · EPSS 0.5%

Published
Updated

Stack: system · node

Affected products and versions

  • deepmerge

    Versions
    • ≥ 0, ≤ 4.3.1: Affected (semver)

    No fix published

  • node-deepmerge Debian:12

    Versions
    • 4.2.2+~1.1.1-3
    • 4.3.1+~1.1.1-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-deepmerge Debian:13

    Versions
    • 4.3.1+~1.1.1-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-deepmerge Debian:14

    Versions
    • 4.3.1+~1.1.1-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • deepmerge npm

    Affected ranges
    • SEMVER: ≥ 4.2.0, ≤ 4.3.1

    No fix published

  • node-deepmerge Ubuntu:22.04:LTS

    Versions
    • 4.2.2-3
    • 4.2.2+~1.1.1-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-deepmerge Ubuntu:24.04:LTS

    Versions
    • 4.2.2+~1.1.1-3
    • 4.3.1+~1.1.1-1build1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-deepmerge Ubuntu:26.10

    Versions
    • 4.3.1+~1.1.1-1build1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-deepmerge Ubuntu:26.04:LTS

    Versions
    • 4.3.1+~1.1.1-1build1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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