CVE Intelligence
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CVE-2026-43899: DeepChat: Electron Pop-up Handler Bypass Enables Arbitrary Protocol Execution

CVE-2026-43899 affects DeepChat versions prior to v1.0.4-beta.1. The record describes an incomplete mitigation for CVE-2025-55733 that left native Electron pop-up handlers unsanitized, allowing a crafted Markdown link to reach shell.openExternal() and bypass the external URL validation. The CNA rates it critical with CVSS 3.1 score 9.6, and the fix is stated to be in v1.0.4-beta.1.

Published Oct 13, 2026 · Updated Oct 13, 2026 · Ler em português

Overview

CVE-2026-43899 is a critical issue in DeepChat, an open-source AI agent platform. According to the record, it is an incomplete fix for CVE-2025-55733. The earlier patch restricted api.openExternal() in the renderer preload script, but native Electron pop-up window handlers were not sanitized. The advisory is published as GitHub Security Advisory GHSA-cp8j-jx7q-7r5f.

Impact

The record states that the flaw can lead to arbitrary protocol execution, described as remote code execution (RCE). The CNA assigns CVSS 3.1 base score 9.6 with vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H, which indicates network attack vector, low complexity, no privileges, user interaction required, scope changed, and high confidentiality, integrity and availability impact. The weakness is classified as CWE-20, Improper Input Validation.

Affected products and versions

  • Product: DeepChat, as described in the record.
  • Affected versions: prior to v1.0.4-beta.1.
  • The record's affected list is empty, so the exact lower bound of affected versions is unknown.

Exploitation status

CISA KEV does not list this CVE in the record. No confirmed exploitation in the wild appears in the sources consulted. The EPSS probability is 0.00559 with percentile 0.45023 as recorded.

Remediation and mitigation

  • Upgrade DeepChat to v1.0.4-beta.1 or later, as stated in the record.
  • Review the advisory linked above for vendor guidance.
  • Until upgrading, limit exposure of DeepChat to untrusted AI endpoints and treat Markdown links from model output with caution.

Detection guidance

  • Inventory DeepChat installations and record their versions.
  • Review logs for unexpected external application launches or protocol handler activity originating from the DeepChat process.
  • Monitor for unusual outbound connections or new processes spawned by the application.

Limitations of the available information

The record does not list fixed or affected version entries, so the exact scope is unknown beyond the description. The EPSS date in the record (2026-10-13) is later than the publication date, so its currency should be verified. No technical reproduction details are provided here by design.

Frequently asked questions

Which DeepChat versions are affected by CVE-2026-43899?

According to the record, versions prior to v1.0.4-beta.1 are affected. The record does not list a precise affected range.

Is CVE-2026-43899 known to be exploited?

CISA KEV does not list this CVE in the record, and no confirmed exploitation appears in the sources consulted.

What should administrators do?

Upgrade DeepChat to v1.0.4-beta.1 or later and limit exposure to untrusted AI endpoints until the upgrade is complete.

This analysis was drafted with AI assistance from verified source data and automatically checked against it.