{"answers":{"affected":"3 open source packages ship an affected version, including jupyter-server and jupyter_server.","exploited":"There is no known exploitation of CVE-2026-86049 in the wild and no public exploit code.","fix":"Upgrade jupyter-server to 2.21.0 or later.","what":"CVE-2026-86049 is a high-severity vulnerability in jupyter-server jupyter_server, published on 17 Sep 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-2026-86049 and fix it if it is affected.\n\nWhat it is: CVE-2026-86049 is a high-severity vulnerability in jupyter-server jupyter_server, published on 17 Sep 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-2026-86049 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- jupyter-server (PyPI): affected all versions; fixed in 2.21.0\n- jupyter-server (PyPI): affected all versions; fixed in 2.21.0\n- jupyter_server (PyPI): affected all versions; fixed in 2.21.0\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-2026-86049/ (Markdown: https://insights.sbomify.com/CVE-2026-86049/index.md)","id":"CVE-2026-86049","markdown":"https://insights.sbomify.com/CVE-2026-86049/index.md","name":"CVE-2026-86049","record":{"aliases":["DEBIAN-CVE-2026-86049","GHSA-c3mw-737p-c7g2","MINI-c7g2-m6hg-q67w","PYSEC-2026-4054","UBUNTU-CVE-2026-86049"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["data_read","account_takeover"],"network_reachable":"yes","non_default_config":false,"product_category":"Jupyter Server","requires_auth":"low_privilege","summary":"Attackers with log access can recover Jupyter tokens from Referer headers in 5xx logs, enabling account takeover.","user_interaction":"required","vuln_class":"information_disclosure"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[],"cvss":{"score":7.1,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-532","name":"Insertion of Sensitive Information into Log File"}],"description":"Jupyter Server is the backend for Jupyter web applications. Prior to version 2.21.0, the 5xx request logging path in jupyter_server/log.py copies the Referer header into a JSON header block without applying the token scrubbing used for the request URI. A request that returns HTTP 500 while the Referer contains a token-bearing URL can therefore write that token to server logs in plaintext. An attacker who can read those logs can recover the token and use the affected user's Jupyter Server permissions. This issue is fixed in version 2.21.0.","ecosystems":["PyPI"],"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: 5xx request logging leaks token-bearing Referer header values","id":"CVE-2026-86049","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"PyPI","product":null,"products":[],"type":"information_disclosure","year":"2026"},"n_packages":3,"n_references":4,"next":{"headline":"Notepad++: Stack Buffer Overflow in `NppParameters::writeSession` via overlong session path","id":"CVE-2026-86054"},"packages":[{"ecosystem":"PyPI","fixed":["2.21.0"],"introduced":["0"],"last_affected":[],"package":"jupyter-server","purl":"pkg:pypi/jupyter-server","source":"GHSA-c3mw-737p-c7g2"},{"ecosystem":"PyPI","fixed":["2.21.0"],"introduced":["0"],"last_affected":[],"package":"jupyter-server","purl":"pkg:pypi/jupyter-server","source":"PYSEC-2026-4054"},{"ecosystem":"PyPI","fixed":["2.21.0"],"introduced":["0"],"last_affected":[],"package":"jupyter_server","purl":null,"source":"GHSA-c3mw-737p-c7g2"}],"prev":{"headline":"MariaDB: Insufficient quoting in mariadb-dump and SHOW commands","id":"CVE-2026-86047"},"products":["jupyter_server"],"published":"2026-09-17","related":[],"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":"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":"2026-09-18","vendors":["jupyter-server"]},"summary":"Attackers with log access can recover Jupyter tokens from Referer headers in 5xx logs, enabling account takeover.","url":"https://insights.sbomify.com/CVE-2026-86049/"}