CVE-2026-93753 deepmerge - Prototype Pollution

deepmerge <= 4.3.1 contains a prototype pollution vulnerability caused by improper validation of keys in mergeObject() function, letting attackers inject properties into object prototypes, exploit requires attacker-controlled source objects.

CVSS base score 7.5 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
EPSS
0.51% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Prototype Pollution
Impact
Denial Of Service
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Published
18 September 2026
Updated
15 October 2026
Weakness
CWE-1321

Vendor fix

Update to the latest version beyond 4.3.1.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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