{"answers":{"affected":"3 open source packages ship an affected version, including jupyter-server. It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-44727 in the wild and no public exploit code.","fix":"Upgrade jupyter-server to 2.20.0 or later.","what":"CVE-2026-44727 is a critical cross-site scripting vulnerability in jupyter-server jupyter_server, published on 22 Jun 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2026-44727 and fix it if it is affected.\n\nWhat it is: CVE-2026-44727 is a critical cross-site scripting vulnerability in jupyter-server jupyter_server, published on 22 Jun 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2026-44727 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- jupyter-server (PyPI): affected all versions; fixed in 2.20.0\n- jupyter-server (PyPI): affected all versions; fixed in 2.20.0\n- jupyter-server (PyPI): affected all versions; fixed in 2.20.0\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-2026-44727/ (Markdown: https://insights.sbomify.com/CVE-2026-44727/index.md)","id":"CVE-2026-44727","markdown":"https://insights.sbomify.com/CVE-2026-44727/index.md","name":"CVE-2026-44727","record":{"aliases":["CLEANSTART-2026-SY39659","DEBIAN-CVE-2026-44727","GHSA-fcw5-x6j4-ccmp","MINI-j8c7-wwpp-pf9r","OESA-2026-3954","OESA-2026-3955","OESA-2026-3956","PYSEC-2026-366","UBUNTU-CVE-2026-44727","openSUSE-SU-2026:11159-1"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["code_execution","account_takeover"],"network_reachable":"yes","non_default_config":false,"product_category":"Jupyter Server","requires_auth":"low_privilege","summary":"Stored XSS in Jupyter Server allows attackers to execute arbitrary code and take over accounts via malicious notebook outputs.","user_interaction":"required","vuln_class":"xss"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"jupyter_server","vendor":"jupyter"}],"cvss":{"score":9.3,"severity":"critical","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H","version":"4.0"},"cwes":[{"id":"CWE-79","name":"Improper Neutralization of Input During Web Page Generation"},{"id":"CWE-1021","name":"Improper Restriction of Rendered UI Layers or Frames"}],"description":"Jupyter Server is the backend for Jupyter web applications. Prior to 2.20, the nbconvert HTTP handlers in jupyter_server render user-authored notebook HTML under the Jupyter origin without a sandbox directive in their Content-Security-Policy. Combined with nbconvert.HTMLExporter's default non-sanitizing behavior, a notebook carrying an HTML payload in a display_data output triggers stored XSS with cookie access, full /api/* authority, and kernel RCE. This vulnerability is fixed in 2.20.","ecosystems":["PyPI","openSUSE:Tumbleweed"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"Jupyter Server: Stored XSS in `NbconvertFileHandler` / `NbconvertPostHandler` via missing `sandbox` CSP","id":"CVE-2026-44727","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"PyPI","product":null,"products":[],"type":"xss","year":"2026"},"n_packages":4,"n_references":2,"next":{"headline":"@babel/plugin-transform-modules-systemjs generates arbitrary code when compiling malicious input","id":"CVE-2026-44728"},"packages":[{"ecosystem":"PyPI","fixed":["2.20.0"],"introduced":["0"],"last_affected":[],"package":"jupyter-server","purl":null,"source":"GHSA-fcw5-x6j4-ccmp"},{"ecosystem":"PyPI","fixed":["2.20.0"],"introduced":["0"],"last_affected":[],"package":"jupyter-server","purl":"pkg:pypi/jupyter-server","source":"GHSA-fcw5-x6j4-ccmp"},{"ecosystem":"PyPI","fixed":["2.20.0"],"introduced":["0"],"last_affected":[],"package":"jupyter-server","purl":"pkg:pypi/jupyter-server","source":"PYSEC-2026-366"},{"ecosystem":"openSUSE:Tumbleweed","fixed":["2.20.0-1.1"],"introduced":["0"],"last_affected":[],"package":"python-jupyter-server","purl":"pkg:rpm/opensuse/python-jupyter-server\u0026distro=openSUSE%20Tumbleweed","source":"openSUSE-SU-2026:11159-1"}],"prev":{"headline":"Deno: TLS retry copies stale upgrade hook, risking plaintext traffic","id":"CVE-2026-44726"},"products":["jupyter_server"],"published":"2026-06-22","related":[{"cvss_score":7.6,"headline":"jupyter-server path traversal allows access to sibling directories sharing root_dir name prefix","id":"CVE-2026-35397","kev_date_added":null,"published":"2026-05-05"},{"cvss_score":7.6,"headline":"jupyter-server CORS origin validation bypass via unanchored regex in allow_origin_pat","id":"CVE-2026-40110","kev_date_added":null,"published":"2026-05-05"},{"cvss_score":7.6,"headline":"jupyter-server authentication cookies remain valid after password reset due to static cookie secret","id":"CVE-2026-40934","kev_date_added":null,"published":"2026-05-05"},{"cvss_score":7.5,"headline":"Jupyter server on Windows discloses Windows user password hash","id":"CVE-2024-35178","kev_date_added":null,"published":"2024-06-06"},{"cvss_score":7.5,"headline":"Sensitive Auth \u0026 Cookie data stored in Jupyter server logs","id":"CVE-2022-24757","kev_date_added":null,"published":"2022-03-23"},{"cvss_score":7.1,"headline":"Known or guessable hidden files may be accessed in Jupyter Server","id":"CVE-2022-29241","kev_date_added":null,"published":"2022-06-14"}],"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":"CC BY 4.0","name":"SUSE","prefix":"openSUSE"},{"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":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-08-28","vendors":["jupyter-server"]},"summary":"Stored XSS in Jupyter Server allows attackers to execute arbitrary code and take over accounts via malicious notebook outputs.","url":"https://insights.sbomify.com/CVE-2026-44727/"}