CVE-2026-43899 - DeepChat: Incomplete Fix for CVE-2025-55733 leads to Remote Code Execution via Markdown Links bypassing `isValidExternalUrl`

CVE-2026-43899 - DeepChat: Incomplete Fix for CVE-2025-55733 leads to Remote Code Execution via Markdown Links bypassing `isValidExternalUrl`

https://cvefeed.io/rssfeed/latest.atom / Tue, 05/12/2026 - 05:23
CVE ID :CVE-2026-43899
Published : May 11, 2026, 11:20 p.m. | 3 hours, 29 minutes ago
Description :DeepChat is an open-source artificial intelligence agent platform that unifies models, tools, and agents. Prior to v1.0.4-beta.1, An incomplete mitigation for CVE-2025-55733 leaves DeepChat vulnerable to an arbitrary protocol execution bypass (RCE). While the patch correctly restricted api.openExternal() inside the renderer's preload/index.ts script, it structurally neglected to sanitize native Electron pop-up window handlers. An attacker or a compromised AI endpoint returning a Markdown link can trigger a target="_blank" native window interception in tabPresenter.ts, which forwards the malicious URL directly to shell.openExternal(url) and completely bypasses the isValidExternalUrl security boundary. This vulnerability is fixed in v1.0.4-beta.1.
Severity: 9.6 | CRITICAL
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Kenya Education Network CERT(KENET-CERT) is a Cybersecurity Emergency Response Team and Co-ordination Center operated by the National Research and Education Network of Kenya. KENET-CERT coordination center promotes awareness on cybersecurity incidences as well as coordinates and assists member institutions in responding effectively to cyber security threats and incidences. KENET-CERT works closely with Kenya's National CIRT coordination center (CIRT/CC) as a sector CIRT for the academic institutions. KENET promotes use of ICT in Teaching, Learning and Research in Higher Education Institutions in Kenya. KENET aims to interconnect all the Universities, Tertiary and Research Institutions in Kenya by setting up a cost effective and sustainable private network with high speed access to the global Internet. KENET also facilitates electronic communication among students and faculties in member institutions, share learning and teaching resources by collaboration in Research and Development of Educational content.