CVE-2026-8657
CWE-1321Published: May 16, 2026· Updated: May 19, 2026
Official 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.
Technical Analysis
CVE-2026-8657 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in full integrity compromise (data manipulation), with a CVSS base score of 8.2.
CVSS v3.1 Vector Breakdown
Exploit & PoC Resources
All References (8)
Quick Facts
Related CVEs (CWE-1321)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-8657 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts