Cross-Site Scripting (XSS) in DeepChat (CVE-2026-43900)
Summary
Cross-site scripting in DeepChat (CVE-2026-43900). Confidential information can be exposed externally. Mitigation: upgrade to 1.0.4-beta.1 or later.
Original description
The description as published by the source.
DeepChat is an open-source artificial intelligence agent platform that unifies models, tools, and agents. Prior to v1.0.4-beta.1, a Cross-Site Scripting (XSS) vulnerability exists due to a discrepancy between the backend validation layer and the frontend browser rendering engine. The SVGSanitizer (src/main/lib/svgSanitizer.ts) restricts script execution by scrubbing javascript: protocols using plain-text regular expressions. However, it fails to account for HTML entity decoding prior to Vue's v-html DOM insertion inside the SvgArtifact.vue component. By feeding an SVG artifact with obfuscated entities (e.g., javascript:alert(1)), an attacker can completely bypass the sanitizer, culminating in arbitrary JavaScript execution when a victim interacts with the rendered SVG Element. This vulnerability is fixed in v1.0.4-beta.1.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-43900 has been found in DeepChat.
Confidential information can be exposed externally. CVSS score: 9.3/10.
What to do: upgrade DeepChat to 1.0.4-beta.1 or later.
If unsure, ask your IT team or search "DeepChat CVE-2026-43900" on the vendor's site.
CVE-2026-43900 (DeepChat) — CWE-79 / CVSS v3 9.3
Attack vector: remote (network-reachable) / unauthenticated
Patched: 1.0.4-beta.1 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
Cross-site scripting (XSS) (CWE-79) exists in DeepChat.
Check the vendor advisory for the affected versions of DeepChat.
Severity: Critical (CVSS 9.3/10). Confidential information can be exposed externally.
Update to 1.0.4-beta.1.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'DeepChat' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'DeepChat' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
DeepChatを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade DeepChat to 1.0.4-beta.1ステージング環境で 1.0.4-beta.1 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
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3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov