CVE-2026-42077 | Evolver: Prototype Pollution via `Object.assign()` in mailbox store operations

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.

Published: 2026-05-04 Last update: 2026-05-07 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-42077 is rated Low Risk (21.8/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.01%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-42077

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-05 — 0.01% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-42077

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.2 3.1 MEDIUM
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 0.5 4.7 [email protected]

Weakness enumeration for CVE-2026-42077

GitHub Security Advisory for CVE-2026-42077

GHSA-2cjr-5v3h-v2w4 · Severity: medium · Ecosystem: npm — Evolver has Prototype Pollution via `Object.assign()` in its mailbox store operations

Affected software / configurations for CVE-2026-42077

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-42077

cvelogic Threat Intelligence