CVE-2026-42077CWE-1321

Evolver: Prototype Pollution via `Object.assign()` in mailbox store operations

Medium · published May 4, 2026

CVSS v3.1
5.2
EPSS
0%
Percentile
19.0
In the wild
Unconfirmed
What it is

Evolver is a GEP-powered self-evolving engine for AI agents. Prior to version 1.69.3, a prototype pollution vulnerability in the mailbox store module allows attackers to modify the behavior of all JavaScript objects by injecting malicious properties into Object.prototype. The vulnerability exists in the _applyUpdate() and _updateRecord() functions which use Object.assign() to merge user-controlled data without filtering dangerous keys like __proto__, constructor, or prototype. This issue has been patched in version 1.69.3.

The record
Technical detail
CVSS v3.1
5.2 · MEDIUM
Vector
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:H
CVSS v4.0
Not supplied
EPSS
0.00276 · 19.0th percentile
Weakness
CWE-1321 · Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')
Published
2026-05-04T16:50Z
EPSS history
Timeline
  • 04 MAY 16:50Z
    Evolver: Prototype Pollution via `Object.assign()` in mailbox store operations
    cvelistv5