{"answers":{"affected":"4 open source packages ship an affected version, including jupyterhub. It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-40864 in the wild and no public exploit code.","fix":"Upgrade jupyterhub to 5.4.5 or later.","what":"CVE-2026-40864 is a medium-severity vulnerability in jupyterhub, published on 22 May 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-2026-40864 and fix it if it is affected.\n\nWhat it is: CVE-2026-40864 is a medium-severity vulnerability in jupyterhub, published on 22 May 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: There is no known exploitation of CVE-2026-40864 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- jupyterhub (Bitnami): affected from 4.1.0; fixed in 5.4.5\n- jupyterhub (PyPI): affected from 4.1.0; fixed in 5.4.5\n- jupyterhub (PyPI): affected from 4.1.0; fixed in 5.4.5\n- jupyterhub (PyPI): affected from 4.1.0; fixed in 5.4.5\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-2026-40864/ (Markdown: https://insights.sbomify.com/CVE-2026-40864/index.md)","id":"CVE-2026-40864","markdown":"https://insights.sbomify.com/CVE-2026-40864/index.md","name":"CVE-2026-40864","record":{"aliases":["BIT-jupyterhub-2026-40864","DEBIAN-CVE-2026-40864","GHSA-m68r-v472-jgq9","PYSEC-2026-2189","UBUNTU-CVE-2026-40864"],"analysis":{"component_type":"web_application","fix_type":"upgrade","impacts":["privilege_escalation","security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"JupyterHub server","requires_auth":"none","summary":"Attackers can bypass XSRF protections to trigger server spawns or force users to accept shared server access via cross-origin form POSTs.","user_interaction":"required","vuln_class":"csrf"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"jupyterhub","vendor":"jupyter"}],"cvss":{"score":5.4,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L","version":"3.1"},"cwes":[{"id":"CWE-352","name":"Cross-Site Request Forgery"}],"description":"JupyterHub is software that allows users to create a multi-user server for Jupyter notebooks. In versions 4.1.0 through 5.4.4, XSRF protection (updated in 4.1.0) inappropriately treated requests with Sec-Fetch-Mode: no-cors as same-origin requests, bypassing XSRF checks. The JSON API is not affected, only HTTP form endpoints, such as /hub/spawn and /hub/accept-share, meaning attackers could trigger server spawn (but not access the server) and if the attacker is a JupyterHub user permitted to share access to their server, cause a user to accept a share and have access to the attacker's server. This issue has been fixed in version 5.4.5. If developers are unable to immediately upgrade, they can temporarily mitigate this issue by dropping requests to JupyterHub with Sec-Fetch-Mode: no-cors if they are using a reverse proxy.","ecosystems":["Bitnami","PyPI"],"exploits":{"exploitdb":0,"first_seen":"2026-06-13","github_poc":1,"max_poc_stars":0,"metasploit":0,"nuclei":0,"refs":[{"date":"2026-06-13T07:11:00Z","kind":"github_poc","ref":"https://github.com/romain-deperne/CVE-2026-40864","stars":0,"title":"JupyterHub CSRF via cross-origin form POST — CVE-2026-40864 / CVSS 5.4"}],"tier":"poc_unverified"},"has_fix":true,"headline":"JupyterHub: Cross-origin form POSTs bypass XSRF","id":"CVE-2026-40864","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Bitnami","product":null,"products":[],"type":"csrf","year":"2026"},"n_packages":4,"n_references":2,"next":{"headline":"Horilla: Insecure Direct Object Reference at `/employee/view-file/\u003cint:id\u003e","id":"CVE-2026-40865"},"packages":[{"ecosystem":"Bitnami","fixed":["5.4.5"],"introduced":["4.1.0"],"last_affected":[],"package":"jupyterhub","purl":"pkg:bitnami/jupyterhub","source":"BIT-jupyterhub-2026-40864"},{"ecosystem":"PyPI","fixed":["5.4.5"],"introduced":["4.1.0"],"last_affected":[],"package":"jupyterhub","purl":null,"source":"GHSA-m68r-v472-jgq9"},{"ecosystem":"PyPI","fixed":["5.4.5"],"introduced":["4.1.0"],"last_affected":[],"package":"jupyterhub","purl":"pkg:pypi/jupyterhub","source":"GHSA-m68r-v472-jgq9"},{"ecosystem":"PyPI","fixed":["5.4.5"],"introduced":["4.1.0"],"last_affected":[],"package":"jupyterhub","purl":"pkg:pypi/jupyterhub","source":"PYSEC-2026-2189"}],"prev":{"headline":"PhpSpreadsheet: CPU Denial of Service via Unbounded Row Index in SpreadsheetML XML Reader","id":"CVE-2026-40863"},"products":["jupyterhub"],"published":"2026-05-22","related":[{"cvss_score":8.1,"headline":"XSS in JupyterHub via Self-XSS leveraged by Cookie Tossing","id":"CVE-2024-28233","kev_date_added":null,"published":"2024-03-27"},{"cvss_score":7.2,"headline":"JupyterHub has a privilege escalation vulnerability with the `admin:users` scope","id":"CVE-2024-41942","kev_date_added":null,"published":"2024-08-08"},{"cvss_score":6.1,"headline":"Open Redirect vulnerability in jupyterhub and notebook","id":"CVE-2019-10255","kev_date_added":null,"published":"2019-03-28"},{"cvss_score":5.1,"headline":"JupyterHub has an Open Redirect Vulnerability","id":"CVE-2026-33709","kev_date_added":null,"published":"2026-04-03"},{"cvss_score":4.5,"headline":"Cross-Site Request Forgery in JupyterHub","id":"CVE-2020-36191","kev_date_added":null,"published":"2021-01-13"},{"cvss_score":3.5,"headline":"incomplete logout in JupyterHub","id":"CVE-2021-41247","kev_date_added":null,"published":"2021-11-04"}],"sources":[{"class":"attribution","licence":"Apache-2.0","name":"Bitnami","prefix":"BIT"},{"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)"},{"class":"open","licence":"CC0","name":"PoC-in-GitHub"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-05-26","vendors":["jupyterhub"]},"summary":"Attackers can bypass XSRF protections to trigger server spawns or force users to accept shared server access via cross-origin form POSTs.","url":"https://insights.sbomify.com/CVE-2026-40864/"}