{"answers":{"affected":"2 open source packages ship an affected version, including tornado.","exploited":"There is no known exploitation of CVE-2026-103261 in the wild and no public exploit code.","fix":"Upgrade tornado to 6.5.9 or later.","what":"CVE-2026-103261 is a medium-severity denial of service vulnerability in tornadoweb tornado, published on 1 Oct 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-2026-103261 and fix it if it is affected.\n\nWhat it is: CVE-2026-103261 is a medium-severity denial of service vulnerability in tornadoweb tornado, published on 1 Oct 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-2026-103261 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- tornado (PyPI): affected all versions; fixed in 6.5.9\n- tornado (PyPI): affected all versions; fixed in 6.5.9\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-2026-103261/ (Markdown: https://insights.sbomify.com/CVE-2026-103261/index.md)","id":"CVE-2026-103261","markdown":"https://insights.sbomify.com/CVE-2026-103261/index.md","name":"CVE-2026-103261","record":{"aliases":["AZL-105372","BELL-CVE-2026-103261","CLEANSTART-2026-IM25560","DEBIAN-CVE-2026-103261","ECHO-5be6-c7b0-c3f1","GHSA-2v9w-f3h6-74rj","GHSA-3hv7-mjh2-fv65","MINI-23jx-2wv4-crr7","MINI-2fg6-6pqc-vm8x","MINI-37vx-2xx5-jqxh","MINI-43gx-jjjr-f2p6","MINI-4f47-p44f-pc2r","MINI-5r9g-93mp-x9qq","MINI-5xc2-7997-8px9","MINI-6rq8-jm2c-5ww5","MINI-7266-w294-pgrg","MINI-79x8-gwwg-r5vp","MINI-c2j9-65gr-x6w4","MINI-c8cp-xhw4-8mww","MINI-gf5g-qxqx-c653","MINI-px33-6px2-7m25","MINI-qmgp-r9cq-p4j7","MINI-rgm6-7jhw-jx2g","MINI-rgwq-66rc-jxqv","MINI-rqmg-mwpp-8f68","MINI-whqp-mjr5-7r24","MINI-wwmh-m5c8-c865","MINI-x86w-4grh-g9gm","UBUNTU-CVE-2026-103261"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Python web framework","requires_auth":"none","summary":"Remote attackers can cause denial of service in Tornado web servers by sending requests with excessive query parameters, stalling the event loop.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"VulnCheck","cpe":[],"cvss":{"score":6.9,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-770","name":"Allocation of Resources Without Limits or Throttling"}],"description":"Tornado before 6.5.9 fails to limit the number of query string fields in HTTPServerRequest.__init__, allowing remote attackers to cause event-loop stalling by sending requests with thousands of query parameters. Attackers can send unauthenticated GET requests with unbounded query-string field counts to degrade response times for all clients sharing the same IOLoop.","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":"Tornado before 6.5.9 Denial of Service via Query String","id":"CVE-2026-103261","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"PyPI","product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":2,"n_references":3,"next":{"headline":"Tornado before 6.5.9 Denial of Service via CurlAsyncHTTPClient","id":"CVE-2026-103262"},"packages":[{"ecosystem":"PyPI","fixed":["6.5.9"],"introduced":["0"],"last_affected":[],"package":"tornado","purl":null,"source":"GHSA-3hv7-mjh2-fv65"},{"ecosystem":"PyPI","fixed":["6.5.9"],"introduced":["0"],"last_affected":[],"package":"tornado","purl":"pkg:pypi/tornado","source":"GHSA-3hv7-mjh2-fv65"}],"prev":{"headline":"n8n before 2.39.6 and 2.40.x before 2.40.1 Approval Bypass via Send and Wait Node","id":"CVE-2026-103260"},"products":["tornado"],"published":"2026-10-01","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":"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":"2026-10-01","vendors":["tornadoweb"]},"summary":"Remote attackers can cause denial of service in Tornado web servers by sending requests with excessive query parameters, stalling the event loop.","url":"https://insights.sbomify.com/CVE-2026-103261/"}