CVE-2026-8657

Prototype Pollution via Unfiltered Delta or JSON Patch Input in jsondiffpatch

Published May 16, 2026 CVSS 4.0 · 8.8 High EPSS < 1% KEV · Not listed
Description
Versions of the package jsondiffpatch before 0.7.6 are vulnerable to Prototype Pollution via the jsondiffpatch.patch() and jsondiffpatch/formatters/jsonpatch.patch() APIs. An attacker can perform prototype pollution by supplying crafted delta or JSON Patch documents, as attacker-controlled property names and path segments are used to traverse and modify objects without restricting access to special properties like __proto__ or constructor.prototype, allowing modification of Object.prototype.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-j4fx-xxwh-2485 jsondiffpatch patch APIs are vulnerable to prototype pollution
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Benjamine
Benjamine jsondiffpatch
Vendors & Products Benjamine
Benjamine jsondiffpatch
Type Values Removed Values Added
Title Prototype Pollution via Unfiltered Delta or JSON Patch Input in jsondiffpatch
Type Values Removed Values Added
Description Versions of the package jsondiffpatch before 0.7.6 are vulnerable to Prototype Pollution via the jsondiffpatch.patch() and jsondiffpatch/formatters/jsonpatch.patch() APIs. An attacker can perform prototype pollution by supplying crafted delta or JSON Patch documents, as attacker-controlled property names and path segments are used to traverse and modify objects without restricting access to special properties like __proto__ or constructor.prototype, allowing modification of Object.prototype.
Weaknesses CWE-1321
References
Metrics cvssV3_1

{'score': 8.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L/E:P'}

cvssV4_0

{'score': 8.8, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/E:P'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
snyk
Published
Updated
Aug 23, 2026, 3:25 PM
Reserved
May 15, 2026, 6:27 AM
Status
Deferred
Published
May 16, 2026, 6:16 AM
Modified
Jul 5, 2026, 4:19 PM