CVE-2026-42077 Evolver: Prototype Pollution via `Object.assign()` in mailbox store operations
Attackers can achieve code execution by injecting malicious properties into Object.prototype via unfiltered user data in mailbox store operations.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-42077?
CVE-2026-42077 is a medium-severity code injection vulnerability in EvoMap evolver, published on 4 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Weakness: CWE-1321
Which versions are affected by CVE-2026-42077?
2 open source packages ship an affected version, including @evomap/evolver.
| Package | Affected | Fixed in |
|---|---|---|
@evomap/evolver npm | All versions | 1.69.3 |
@evomap/evolver npm | All versions | 1.69.3 |
How do I fix CVE-2026-42077?
Upgrade @evomap/evolver to 1.69.3 or later.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-42077 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-42077 exists.
Sources
Also known as GHSA-2cjr-5v3h-v2w4.