CVE-2026-93753
highdeepmerge through 4.3.1 contains a prototype poisoning vulnerability in the mergeObject() function that fails to properly validate keys being written to target…
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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://github.com/TehShrike/deepmerge disclosure@vulncheck.com
- https://github.com/TehShrike/deepmerge/blob/5b87756a5671635679001cbac72aa42f23472c81/index... disclosure@vulncheck.com
- https://github.com/TehShrike/deepmerge/issues/273 disclosure@vulncheck.com
- https://www.vulncheck.com/advisories/deepmerge-through-4.3.1-prototype-poisoning-via-merge... disclosure@vulncheck.com
- https://github.com/TehShrike/deepmerge/issues/273 134c704f-9b21-4f2e-91b3-4a467353bcc0