Information Disclosure in nicegui (CVE-2026-45553)
Summary
Vulnerability in nicegui (CVE-2026-45553). Confidential information can be exposed externally. Exploitable via include. Mitigation: upgrade to 3.12.0 or later.
Original description
The description as published by the source.
Summary
ui.restructured_text() renders reStructuredText server-side with Docutils without disabling file insertion directives.
When a NiceGUI application passes attacker-controlled content to ui.restructured_text(), an attacker can use standard Docutils directives (include, csv-table with :file:, raw with :file:) to read local files readable by the NiceGUI server process.
Applications that only pass trusted static strings to ui.restructured_text() are not affected.
Details
The affected component is the reStructuredText renderer:
- File:
nicegui/elements/restructured_text.py - Function:
prepare_content()
prepare_content() renders user-supplied reStructuredText through Docutils:
html = publish_parts(
remove_indentation(content),
writer_name='html4',
settings_overrides={'syntax_highlight': 'short'},
)
The Docutils call only sets syntax_highlight. It does not disable file insertion or raw directives, so Docutils processes directives that read local files and embed their contents into the generated HTML before it is returned to the browser. Frontend sanitization cannot prevent this because the file has already been read server-side.
A minimal vulnerable usage pattern is any page that forwards untrusted input into ui.restructured_text(), e.g. content taken from query parameters, form fields, or other user-controlled sources.
Impact
Local file disclosure. An attacker who can supply reStructuredText content c…
Source: GitHub Security Advisories (Global) 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-2026-45553 has been found in nicegui.
Attackers can target a specific entry point like include over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 7.5/10.
What to do: upgrade nicegui to 3.12.0 or later.
If unsure, ask your IT team or search "nicegui CVE-2026-45553" on the vendor's site.
CVE-2026-45553 (nicegui) — CWE-200 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: include / raw / syntax_highlight / docutils.conf
Patched: 3.12.0 — 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.
Information disclosure (CWE-200) exists in nicegui. Attackers reach the vulnerable code path via include without authentication.
Check the vendor advisory for the affected versions of nicegui. Attack surface: include / raw / syntax_highlight / docutils.conf.
Severity: High (CVSS 7.5/10). Confidential information can be exposed externally.
Update to 3.12.0.
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 'nicegui' . 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
-
1Identify exposure identify
grep -r 'nicegui' . | 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
nicegui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 nicegui to 3.12.0ステージング環境で 3.12.0 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。
-
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。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com