{"answers":{"affected":"3 open source packages ship an affected version, including tornado.","exploited":"There is no known exploitation of CVE-2026-49855 in the wild and no public exploit code.","fix":"Upgrade tornado to 6.5.6 or later.","what":"CVE-2026-49855 is a high-severity denial of service vulnerability in tornadoweb tornado, published on 14 Jul 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-2026-49855 and fix it if it is affected.\n\nWhat it is: CVE-2026-49855 is a high-severity denial of service vulnerability in tornadoweb tornado, published on 14 Jul 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-2026-49855 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- tornado (PyPI): affected all versions; fixed in 6.5.6\n- tornado (PyPI): affected all versions; fixed in 6.5.6\n- tornado (PyPI): affected all versions; fixed in 6.5.6\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-2026-49855/ (Markdown: https://insights.sbomify.com/CVE-2026-49855/index.md)","id":"CVE-2026-49855","markdown":"https://insights.sbomify.com/CVE-2026-49855/index.md","name":"CVE-2026-49855","record":{"aliases":["AZL-92385","BELL-CVE-2026-49855","CLEANSTART-2026-QK13571","CLSA-2026-1781744125","DEBIAN-CVE-2026-49855","ECHO-7775-eb27-2601","GHSA-mgf9-4vpg-hj56","MINI-5wfw-h46w-v3p9","MINI-9wg5-hpcf-rcpx","MINI-f5f3-v65f-hrgv","MINI-frcv-qj4f-j8cv","MINI-hf67-x9c8-783j","MINI-jhcw-fxwg-6qqw","MINI-m32x-92cm-ppw7","MINI-r34c-8x5q-w558","MINI-w3m5-7r3p-7qwh","PYSEC-2026-3389","ROOT-APP-PYPI-CVE-2026-49855","UBUNTU-CVE-2026-49855"],"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":"A malicious server can cause memory exhaustion in Tornado's AsyncHTTPClient by sending a gzip bomb, leading to denial of service.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[],"cvss":{"score":7.5,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-409","name":"Improper Handling of Highly Compressed Data (Data Amplification)"}],"description":"Tornado is a Python web framework and asynchronous networking library. Prior to 6.5.6, Tornado gzip decompression routines processed limited-size chunks but did not enforce an overall limit on accumulated decompressed chunks, allowing a malicious server accessed by SimpleAsyncHTTPClient or an HTTPServer configured with decompress_request=True to consume effectively unlimited memory. This issue is fixed in version 6.5.6.","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 AsyncHTTPClient accumulates decompressed chunks without size limit (gzip bomb)","id":"CVE-2026-49855","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"PyPI","product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":3,"n_references":3,"next":{"headline":"@jshookmcp/jshook: ICMP probe and traceroute skip local-network SSRF authorization","id":"CVE-2026-49856"},"packages":[{"ecosystem":"PyPI","fixed":["6.5.6"],"introduced":["0"],"last_affected":[],"package":"tornado","purl":null,"source":"GHSA-mgf9-4vpg-hj56"},{"ecosystem":"PyPI","fixed":["6.5.6"],"introduced":["0"],"last_affected":[],"package":"tornado","purl":"pkg:pypi/tornado","source":"GHSA-mgf9-4vpg-hj56"},{"ecosystem":"PyPI","fixed":["6.5.6"],"introduced":["0"],"last_affected":[],"package":"tornado","purl":"pkg:pypi/tornado","source":"PYSEC-2026-3389"}],"prev":{"headline":"Tornado: Out-of-bounds memory access in C extension","id":"CVE-2026-49854"},"products":["tornado"],"published":"2026-07-14","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":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-07-16","vendors":["tornadoweb"]},"summary":"A malicious server can cause memory exhaustion in Tornado's AsyncHTTPClient by sending a gzip bomb, leading to denial of service.","url":"https://insights.sbomify.com/CVE-2026-49855/"}