{"answers":{"affected":"4 open source packages ship an affected version, including jupyterhub.","exploited":"There is no known exploitation of CVE-2026-54338 in the wild and no public exploit code.","fix":"Upgrade jupyterhub to 5.5.0 or later.","what":"CVE-2026-54338 is a medium-severity denial of service vulnerability in jupyterhub, published on 7 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-54338 and fix it if it is affected.\n\nWhat it is: CVE-2026-54338 is a medium-severity denial of service vulnerability in jupyterhub, published on 7 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-54338 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- jupyterhub (Bitnami): affected all versions; fixed in 5.5.0\n- jupyterhub (PyPI): affected all versions; fixed in 5.5.0\n- jupyterhub (PyPI): affected all versions; fixed in 5.5.0\n- jupyterhub (PyPI): affected all versions; fixed in 5.5.0\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-2026-54338/ (Markdown: https://insights.sbomify.com/CVE-2026-54338/index.md)","id":"CVE-2026-54338","markdown":"https://insights.sbomify.com/CVE-2026-54338/index.md","name":"CVE-2026-54338","record":{"aliases":["BIT-jupyterhub-2026-54338","DEBIAN-CVE-2026-54338","GHSA-p43p-whwx-q52h","PYSEC-2026-3853","UBUNTU-CVE-2026-54338"],"analysis":{"component_type":"web_application","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"JupyterHub","requires_auth":"none","summary":"Unauthenticated attackers can cause denial of service by submitting invalid login attempts with unbounded usernames, consuming logging and storage resources.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[],"cvss":{"score":5.3,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","version":"3.1"},"cwes":[{"id":"CWE-400","name":"Uncontrolled Resource Consumption"}],"description":"JupyterHub is software that allows users to create a multi-user server for Jupyter notebooks. Prior to 5.5.0, invalid input to form-based login authenticators can place an unbounded attacker-controlled username in failed-login logs, allowing an unauthenticated attacker to consume logging and storage resources. This issue is fixed in version 5.5.0.","ecosystems":["Bitnami","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":"JupyterHub: Unauthenticated Denial of Service via Unbounded Username Logging on Failed Login","id":"CVE-2026-54338","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Bitnami","product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":4,"n_references":2,"next":{"headline":"Glean: Server-Side Request Forgery (SSRF) with Full Response Disclosure via Malicious RSS Feed in /api/feeds/discover","id":"CVE-2026-54339"},"packages":[{"ecosystem":"Bitnami","fixed":["5.5.0"],"introduced":["0"],"last_affected":[],"package":"jupyterhub","purl":"pkg:bitnami/jupyterhub","source":"BIT-jupyterhub-2026-54338"},{"ecosystem":"PyPI","fixed":["5.5.0"],"introduced":["0"],"last_affected":[],"package":"jupyterhub","purl":null,"source":"GHSA-p43p-whwx-q52h"},{"ecosystem":"PyPI","fixed":["5.5.0"],"introduced":["0"],"last_affected":[],"package":"jupyterhub","purl":"pkg:pypi/jupyterhub","source":"GHSA-p43p-whwx-q52h"},{"ecosystem":"PyPI","fixed":["5.5.0"],"introduced":["0"],"last_affected":[],"package":"jupyterhub","purl":"pkg:pypi/jupyterhub","source":"PYSEC-2026-3853"}],"prev":{"headline":"Fireshare has Unauthenticated Argument Injection to Arbitrary File Write/Overwrite","id":"CVE-2026-54337"},"products":["jupyterhub"],"published":"2026-08-07","related":[],"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":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-08-11","vendors":["jupyterhub"]},"summary":"Unauthenticated attackers can cause denial of service by submitting invalid login attempts with unbounded usernames, consuming logging and storage resources.","url":"https://insights.sbomify.com/CVE-2026-54338/"}