{"answers":{"affected":"3 open source packages ship an affected version, including nicegui. It affects 1 product.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-21872 exists.","fix":"Upgrade nicegui to 3.5.0 or later.","what":"CVE-2026-21872 is a medium-severity cross-site scripting vulnerability in zauberzeug nicegui, published on 8 Jan 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2026-21872 and fix it if it is affected.\n\nWhat it is: CVE-2026-21872 is a medium-severity cross-site scripting vulnerability in zauberzeug nicegui, published on 8 Jan 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-21872 exists.\n\nAffected packages and fixed versions:\n- nicegui (PyPI): affected from 2.22.0; fixed in 3.5.0\n- nicegui (PyPI): affected from 2.22.0; fixed in 3.5.0\n- nicegui (PyPI): affected from 2.22.0; fixed in 3.5.0\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-21872/ (Markdown: https://insights.sbomify.com/CVE-2026-21872/index.md)","id":"CVE-2026-21872","markdown":"https://insights.sbomify.com/CVE-2026-21872/index.md","name":"CVE-2026-21872","record":{"aliases":["GHSA-m7j5-rq9j-6jj9","PYSEC-2026-1701"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["code_execution"],"network_reachable":"yes","non_default_config":false,"product_category":"Python UI framework","requires_auth":"none","summary":"An attacker can execute arbitrary JavaScript in a victim's browser via malicious links in NiceGUI sub-pages, requiring user interaction.","user_interaction":"required","vuln_class":"xss"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"nicegui","vendor":"zauberzeug"}],"cvss":{"score":6.1,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","version":"3.1"},"cwes":[{"id":"CWE-79","name":"Improper Neutralization of Input During Web Page Generation"}],"description":"NiceGUI is a Python-based UI framework. From versions 2.22.0 to 3.4.1, an unsafe implementation in the click event listener used by ui.sub_pages, combined with attacker-controlled link rendering on the page, causes XSS when the user actively clicks on the link. This issue has been patched in version 3.5.0.","ecosystems":["PyPI"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":true,"headline":"NiceGUI apps are vulnerable to XSS which uses `ui.sub_pages` and render arbitrary user-provided links","id":"CVE-2026-21872","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"PyPI","product":null,"products":[],"type":"xss","year":"2026"},"n_packages":3,"n_references":2,"next":{"headline":"Zero-click XSS in all NiceGUI apps which uses `ui.sub_pages`","id":"CVE-2026-21873"},"packages":[{"ecosystem":"PyPI","fixed":["3.5.0"],"introduced":["2.22.0"],"last_affected":[],"package":"nicegui","purl":null,"source":"GHSA-m7j5-rq9j-6jj9"},{"ecosystem":"PyPI","fixed":["3.5.0"],"introduced":["2.22.0"],"last_affected":[],"package":"nicegui","purl":"pkg:pypi/nicegui","source":"GHSA-m7j5-rq9j-6jj9"},{"ecosystem":"PyPI","fixed":["3.5.0"],"introduced":["2.22.0"],"last_affected":[],"package":"nicegui","purl":"pkg:pypi/nicegui","source":"PYSEC-2026-1701"}],"prev":{"headline":"NiceGUI is vulnerable to XSS via Unescaped URL in ui.navigate.history.push() / replace()","id":"CVE-2026-21871"},"products":["nicegui"],"published":"2026-01-08","related":[{"cvss_score":7.5,"headline":"NiceGUI's Path Traversal via Unsanitized FileUpload.name Enables Arbitrary File Write","id":"CVE-2026-25732","kev_date_added":null,"published":"2026-02-06"},{"cvss_score":7.5,"headline":"NiceGUI Path Traversal Vulnerability in app.add_media_files() Allows Arbitrary File Reading","id":"CVE-2025-66645","kev_date_added":null,"published":"2025-12-09"},{"cvss_score":7.2,"headline":"Zero-click XSS in all NiceGUI apps which uses `ui.sub_pages`","id":"CVE-2026-21873","kev_date_added":null,"published":"2026-01-08"},{"cvss_score":6.9,"headline":"NiceGUI's unvalidated chunk size parameter in media routes can cause memory exhaustion","id":"CVE-2026-33332","kev_date_added":null,"published":"2026-03-24"},{"cvss_score":6.1,"headline":"NiceGUI has XSS via Code Injection","id":"CVE-2026-27156","kev_date_added":null,"published":"2026-02-24"},{"cvss_score":6.1,"headline":"NiceGUI's XSS vulnerability in ui.markdown() allows arbitrary JavaScript execution through unsanitized HTML content","id":"CVE-2026-25516","kev_date_added":null,"published":"2026-02-06"},{"cvss_score":6.1,"headline":"NiceGUI is vulnerable to XSS via Unescaped URL in ui.navigate.history.push() / replace()","id":"CVE-2026-21871","kev_date_added":null,"published":"2026-01-08"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"CC BY 4.0","name":"PyPA Advisory Database","prefix":"PYSEC"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"poc","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-01-08","vendors":["zauberzeug"]},"summary":"An attacker can execute arbitrary JavaScript in a victim's browser via malicious links in NiceGUI sub-pages, requiring user interaction.","url":"https://insights.sbomify.com/CVE-2026-21872/"}