PT-2026-39859 · Deepchat · Deepchat

Ylchen-007 · Published 2026-05-11 · Updated 2026-05-12 · CVE-2026-43899

Positive Technologies (AI Summary)

CVSS v3.1

9.6

Critical

Base vector

AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions DeepChat versions prior to 1.0.4-beta.1

Description An incomplete mitigation for a previous issue allows for an arbitrary protocol execution bypass, which can lead to remote code execution (RCE). While restrictions were applied to the api.openExternal() function within the renderer's preload/index.ts script, native Electron pop-up window handlers were not sanitized. An attacker or a compromised AI endpoint can provide a Markdown link that triggers a target=" blank" native window interception in tabPresenter.ts. This process forwards the malicious URL directly to shell.openExternal(url), bypassing the isValidExternalUrl security boundary.

Recommendations Update to version 1.0.4-beta.1.

Exploit

Fix

RCE

Weakness Enumeration

CWE-20

Related Identifiers

CVE-2026-43899

Affected Products

Deepchat

References · 6

• 🔥 https://github.com/ThinkInAIXYZ/deepchat/security/advisories/GHSA-cp8j-jx7q-7r5f · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2026-43899 · Security Note
• https://twitter.com/KaitanSecurity/status/2053988535355535692 · Twitter Post
• https://t.me/cveNotify/163145 · Telegram Post
• https://t.me/CVEtracker/53430 · Telegram Post
• https://twitter.com/VulmonFeeds/status/2054158812525813805 · Twitter Post