What is CVE-2026-8657?

CVE-2026-8657 is a high-severity vulnerability in Jsondiffpatch, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 8.2/10. Published 2026-05-16.

How severe is CVE-2026-8657?

High severity. CVSS v3 base score is 8.2 out of 10.

Prototype Pollution in Jsondiffpatch

CVE-2026-8657

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 de…

Vulnerability class: Prototype Pollution

EPSS: 0.001 (20.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:L.

Affected products

N/a Jsondiffpatch — versions 0

Weakness classification (CWE)

CWE-1321 — Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution)

References

Frequently asked questions

What is CVE-2026-8657?: CVE-2026-8657 is a high-severity vulnerability in Jsondiffpatch, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 8.2/10. Published 2026-05-16.
How severe is CVE-2026-8657?: High severity. CVSS v3 base score is 8.2 out of 10.