{"answers":{"affected":"3 open source packages ship an affected version, including urllib3. It affects 1 product.","exploited":"There is no known exploitation of CVE-2025-66471 in the wild and no public exploit code.","fix":"Upgrade urllib3 to 2.6.0 or later.","what":"CVE-2025-66471 is a high-severity denial of service vulnerability in urllib3, published on 5 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2025-66471 and fix it if it is affected.\n\nWhat it is: CVE-2025-66471 is a high-severity denial of service vulnerability in urllib3, published on 5 Dec 2025. 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-2025-66471 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- urllib3 (PyPI): affected from 1.0; fixed in 2.6.0\n- urllib3 (PyPI): affected from 1.0; fixed in 2.6.0\n- urllib3 (PyPI): affected from 1.0; fixed in 2.6.0\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-2025-66471/ (Markdown: https://insights.sbomify.com/CVE-2025-66471/index.md)","id":"CVE-2025-66471","markdown":"https://insights.sbomify.com/CVE-2025-66471/index.md","name":"CVE-2025-66471","record":{"aliases":["ALPINE-CVE-2025-66471","AZL-71837","AZL-71849","BELL-CVE-2025-66471","CLEANSTART-2026-JR23071","CLSA-2026-1770035896","CLSA-2026-1770046658","CLSA-2026-1787220376","DEBIAN-CVE-2025-66471","ECHO-c1ca-549f-f62b","GHSA-2xpw-w6gg-jr37","MINI-29g2-46wq-pw5x","MINI-2xv4-2mfg-wrr2","MINI-32jp-fmxp-x89h","MINI-38w9-v5vg-h9p3","MINI-5q6x-83cw-qvh4","MINI-cpr6-qwph-69pf","MINI-cw32-j3fw-5gjr","MINI-gjgm-ch9r-mgm7","MINI-h5w5-c8cv-j4vf","MINI-j76w-f2cm-vvqr","MINI-jp2h-32gh-w4cx","MINI-r38x-pgr5-94j5","MINI-x2xm-r5xf-pvr2","OESA-2026-1249","OESA-2026-1250","OESA-2026-1286","PYSEC-2026-1994","RHSA-2026:11722","RHSA-2026:1795","RHSA-2026:2060","RHSA-2026:9031","ROOT-APP-PYPI-CVE-2025-66471","SUSE-RU-2026:21397-1","SUSE-RU-2026:21430-1","SUSE-SU-2026:1067-1","SUSE-SU-2026:2854-1","SUSE-SU-2026:2854-2","UBUNTU-CVE-2025-66471","USN-7927-2","USN-7927-3","USN-8344-3","openSUSE-RU-2026:20649-1"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Python HTTP client library","requires_auth":"none","summary":"Attackers can cause excessive CPU and memory consumption in urllib3 by sending highly compressed data, 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":[{"product":"urllib3","vendor":"python"}],"cvss":{"score":8.9,"severity":"high","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H","version":"4.0"},"cwes":[{"id":"CWE-409","name":"Improper Handling of Highly Compressed Data (Data Amplification)"}],"description":"urllib3 is a user-friendly HTTP client library for Python. Starting in version 1.0 and prior to 2.6.0, the Streaming API improperly handles highly compressed data. urllib3's streaming API is designed for the efficient handling of large HTTP responses by reading the content in chunks, rather than loading the entire response body into memory at once. When streaming a compressed response, urllib3 can perform decoding or decompression based on the HTTP Content-Encoding header (e.g., gzip, deflate, br, or zstd). The library must read compressed data from the network and decompress it until the requested chunk size is met. Any resulting decompressed data that exceeds the requested amount is held in an internal buffer for the next read operation. The decompression logic could cause urllib3 to fully decode a small amount of highly compressed data in a single operation. This can result in excessive resource consumption (high CPU usage and massive memory allocation for the decompressed data.","ecosystems":["PyPI","Red Hat:enterprise_linux:7::server","Red Hat:rhel_els:6","Red Hat:rhel_els:7","Red Hat:rhel_extras_sap_els:7","Red Hat:rhel_extras_sap_hana_els:7","SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS","SUSE:Linux Enterprise High Performance Computing 15 SP4-LTSS","SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS","SUSE:Linux Enterprise High Performance Computing 15 SP5-LTSS","SUSE:Linux Enterprise Micro 5.2","SUSE:Linux Enterprise Micro 5.3","SUSE:Linux Enterprise Micro 5.4","SUSE:Linux Enterprise Micro 5.5","SUSE:Linux Enterprise Module for Basesystem 15 SP7","SUSE:Linux Enterprise Server 15 SP4-LTSS","SUSE:Linux Enterprise Server 15 SP5-LTSS","SUSE:Linux Enterprise Server 15 SP6-LTSS","SUSE:Linux Enterprise Server for SAP Applications 15 SP4","SUSE:Linux Enterprise Server for SAP Applications 15 SP5","SUSE:Linux Enterprise Server for SAP Applications 15 SP6"],"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":"urllib3 Streaming API improperly handles highly compressed data","id":"CVE-2025-66471","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"PyPI","product":null,"products":[],"type":"denial_of_service","year":"2025"},"n_packages":37,"n_references":2,"next":{"headline":"XWiki vulnerable to a reflected XSS via xredirect parameter in DeleteApplication","id":"CVE-2025-66472"},"packages":[{"ecosystem":"PyPI","fixed":["2.6.0"],"introduced":["1.0"],"last_affected":[],"package":"urllib3","purl":null,"source":"GHSA-2xpw-w6gg-jr37"},{"ecosystem":"PyPI","fixed":["2.6.0"],"introduced":["1.0"],"last_affected":[],"package":"urllib3","purl":"pkg:pypi/urllib3","source":"GHSA-2xpw-w6gg-jr37"},{"ecosystem":"PyPI","fixed":["2.6.0"],"introduced":["1.0"],"last_affected":[],"package":"urllib3","purl":"pkg:pypi/urllib3","source":"PYSEC-2026-1994"},{"ecosystem":"Red Hat:enterprise_linux:7::server","fixed":["0:0.1.13-1.el7_9.5"],"introduced":["0"],"last_affected":[],"package":"python-s3transfer","purl":"pkg:rpm/redhat/python-s3transfer","source":"RHSA-2026:2060"},{"ecosystem":"Red Hat:enterprise_linux:7::server","fixed":["0:4.1.1-61.el7_9.22"],"introduced":["0"],"last_affected":[],"package":"resource-agents","purl":"pkg:rpm/redhat/resource-agents","source":"RHSA-2026:1795"},{"ecosystem":"Red Hat:enterprise_linux:7::server","fixed":["0:4.1.1-61.el7_9.22"],"introduced":["0"],"last_affected":[],"package":"resource-agents-aliyun","purl":"pkg:rpm/redhat/resource-agents-aliyun","source":"RHSA-2026:1795"},{"ecosystem":"Red Hat:enterprise_linux:7::server","fixed":["0:4.1.1-61.el7_9.22"],"introduced":["0"],"last_affected":[],"package":"resource-agents-debuginfo","purl":"pkg:rpm/redhat/resource-agents-debuginfo","source":"RHSA-2026:1795"},{"ecosystem":"Red Hat:enterprise_linux:7::server","fixed":["0:4.1.1-61.el7_9.22"],"introduced":["0"],"last_affected":[],"package":"resource-agents-gcp","purl":"pkg:rpm/redhat/resource-agents-gcp","source":"RHSA-2026:1795"},{"ecosystem":"Red Hat:rhel_els:6","fixed":["0:1.10.2-3.el6_10.1"],"introduced":["0"],"last_affected":[],"package":"python-urllib3","purl":"pkg:rpm/redhat/python-urllib3","source":"RHSA-2026:11722"},{"ecosystem":"Red Hat:rhel_els:7","fixed":["0:1.10.2-7.el7_9.1"],"introduced":["0"],"last_affected":[],"package":"python-urllib3","purl":"pkg:rpm/redhat/python-urllib3","source":"RHSA-2026:9031"},{"ecosystem":"Red Hat:rhel_extras_sap_els:7","fixed":["0:4.1.1-61.el7_9.22"],"introduced":["0"],"last_affected":[],"package":"resource-agents","purl":"pkg:rpm/redhat/resource-agents","source":"RHSA-2026:1795"},{"ecosystem":"Red Hat:rhel_extras_sap_els:7","fixed":["0:4.1.1-61.el7_9.22"],"introduced":["0"],"last_affected":[],"package":"resource-agents-debuginfo","purl":"pkg:rpm/redhat/resource-agents-debuginfo","source":"RHSA-2026:1795"},{"ecosystem":"Red Hat:rhel_extras_sap_els:7","fixed":["0:4.1.1-61.el7_9.22"],"introduced":["0"],"last_affected":[],"package":"resource-agents-sap","purl":"pkg:rpm/redhat/resource-agents-sap","source":"RHSA-2026:1795"},{"ecosystem":"Red Hat:rhel_extras_sap_els:7","fixed":["0:3.0.1-37.el7_9.22"],"introduced":["0"],"last_affected":[],"package":"sap-cluster-connector","purl":"pkg:rpm/redhat/sap-cluster-connector","source":"RHSA-2026:1795"},{"ecosystem":"Red Hat:rhel_extras_sap_hana_els:7","fixed":["0:4.1.1-61.el7_9.22"],"introduced":["0"],"last_affected":[],"package":"resource-agents","purl":"pkg:rpm/redhat/resource-agents","source":"RHSA-2026:1795"},{"ecosystem":"Red Hat:rhel_extras_sap_hana_els:7","fixed":["0:4.1.1-61.el7_9.22"],"introduced":["0"],"last_affected":[],"package":"resource-agents-debuginfo","purl":"pkg:rpm/redhat/resource-agents-debuginfo","source":"RHSA-2026:1795"},{"ecosystem":"Red Hat:rhel_extras_sap_hana_els:7","fixed":["0:4.1.1-61.el7_9.22"],"introduced":["0"],"last_affected":[],"package":"resource-agents-sap-hana","purl":"pkg:rpm/redhat/resource-agents-sap-hana","source":"RHSA-2026:1795"},{"ecosystem":"Red Hat:rhel_extras_sap_hana_els:7","fixed":["0:0.164.0-6.el7_9.22"],"introduced":["0"],"last_affected":[],"package":"resource-agents-sap-hana-scaleout","purl":"pkg:rpm/redhat/resource-agents-sap-hana-scaleout","source":"RHSA-2026:1795"},{"ecosystem":"SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS","fixed":["1.25.10-150300.4.30.1"],"introduced":["0"],"last_affected":[],"package":"python-urllib3","purl":"pkg:rpm/suse/python-urllib3\u0026distro=SUSE%20Linux%20Enterprise%20High%20Performance%20Computing%2015%20SP4-ESPOS","source":"SUSE-SU-2026:2854-2"},{"ecosystem":"SUSE:Linux Enterprise High Performance Computing 15 SP4-LTSS","fixed":["1.25.10-150300.4.30.1"],"introduced":["0"],"last_affected":[],"package":"python-urllib3","purl":"pkg:rpm/suse/python-urllib3\u0026distro=SUSE%20Linux%20Enterprise%20High%20Performance%20Computing%2015%20SP4-LTSS","source":"SUSE-SU-2026:2854-2"},{"ecosystem":"SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS","fixed":["1.25.10-150300.4.30.1"],"introduced":["0"],"last_affected":[],"package":"python-urllib3","purl":"pkg:rpm/suse/python-urllib3\u0026distro=SUSE%20Linux%20Enterprise%20High%20Performance%20Computing%2015%20SP5-ESPOS","source":"SUSE-SU-2026:2854-2"},{"ecosystem":"SUSE:Linux Enterprise High Performance Computing 15 SP5-LTSS","fixed":["1.25.10-150300.4.30.1"],"introduced":["0"],"last_affected":[],"package":"python-urllib3","purl":"pkg:rpm/suse/python-urllib3\u0026distro=SUSE%20Linux%20Enterprise%20High%20Performance%20Computing%2015%20SP5-LTSS","source":"SUSE-SU-2026:2854-2"},{"ecosystem":"SUSE:Linux Enterprise Micro 5.2","fixed":["1.25.10-150300.4.24.1"],"introduced":["0"],"last_affected":[],"package":"python-urllib3","purl":"pkg:rpm/suse/python-urllib3\u0026distro=SUSE%20Linux%20Enterprise%20Micro%205.2","source":"SUSE-SU-2026:1067-1"},{"ecosystem":"SUSE:Linux Enterprise Micro 5.3","fixed":["1.25.10-150300.4.24.1"],"introduced":["0"],"last_affected":[],"package":"python-urllib3","purl":"pkg:rpm/suse/python-urllib3\u0026distro=SUSE%20Linux%20Enterprise%20Micro%205.3","source":"SUSE-SU-2026:1067-1"},{"ecosystem":"SUSE:Linux Enterprise Micro 5.3","fixed":["1.25.10-150300.4.30.1"],"introduced":["0"],"last_affected":[],"package":"python-urllib3","purl":"pkg:rpm/suse/python-urllib3\u0026distro=SUSE%20Linux%20Enterprise%20Micro%205.3","source":"SUSE-SU-2026:2854-1"},{"ecosystem":"SUSE:Linux Enterprise Micro 5.4","fixed":["1.25.10-150300.4.24.1"],"introduced":["0"],"last_affected":[],"package":"python-urllib3","purl":"pkg:rpm/suse/python-urllib3\u0026distro=SUSE%20Linux%20Enterprise%20Micro%205.4","source":"SUSE-SU-2026:1067-1"},{"ecosystem":"SUSE:Linux Enterprise Micro 5.4","fixed":["1.25.10-150300.4.30.1"],"introduced":["0"],"last_affected":[],"package":"python-urllib3","purl":"pkg:rpm/suse/python-urllib3\u0026distro=SUSE%20Linux%20Enterprise%20Micro%205.4","source":"SUSE-SU-2026:2854-1"},{"ecosystem":"SUSE:Linux Enterprise Micro 5.5","fixed":["1.25.10-150300.4.24.1"],"introduced":["0"],"last_affected":[],"package":"python-urllib3","purl":"pkg:rpm/suse/python-urllib3\u0026distro=SUSE%20Linux%20Enterprise%20Micro%205.5","source":"SUSE-SU-2026:1067-1"},{"ecosystem":"SUSE:Linux Enterprise Micro 5.5","fixed":["1.25.10-150300.4.30.1"],"introduced":["0"],"last_affected":[],"package":"python-urllib3","purl":"pkg:rpm/suse/python-urllib3\u0026distro=SUSE%20Linux%20Enterprise%20Micro%205.5","source":"SUSE-SU-2026:2854-1"},{"ecosystem":"SUSE:Linux Enterprise Module for Basesystem 15 SP7","fixed":["1.25.10-150300.4.24.1"],"introduced":["0"],"last_affected":[],"package":"python-urllib3","purl":"pkg:rpm/suse/python-urllib3\u0026distro=SUSE%20Linux%20Enterprise%20Module%20for%20Basesystem%2015%20SP7","source":"SUSE-SU-2026:1067-1"},{"ecosystem":"SUSE:Linux Enterprise Module for Basesystem 15 SP7","fixed":["1.25.10-150300.4.30.1"],"introduced":["0"],"last_affected":[],"package":"python-urllib3","purl":"pkg:rpm/suse/python-urllib3\u0026distro=SUSE%20Linux%20Enterprise%20Module%20for%20Basesystem%2015%20SP7","source":"SUSE-SU-2026:2854-1"},{"ecosystem":"SUSE:Linux Enterprise Server 15 SP4-LTSS","fixed":["1.25.10-150300.4.30.1"],"introduced":["0"],"last_affected":[],"package":"python-urllib3","purl":"pkg:rpm/suse/python-urllib3\u0026distro=SUSE%20Linux%20Enterprise%20Server%2015%20SP4-LTSS","source":"SUSE-SU-2026:2854-2"},{"ecosystem":"SUSE:Linux Enterprise Server 15 SP5-LTSS","fixed":["1.25.10-150300.4.30.1"],"introduced":["0"],"last_affected":[],"package":"python-urllib3","purl":"pkg:rpm/suse/python-urllib3\u0026distro=SUSE%20Linux%20Enterprise%20Server%2015%20SP5-LTSS","source":"SUSE-SU-2026:2854-2"},{"ecosystem":"SUSE:Linux Enterprise Server 15 SP6-LTSS","fixed":["1.25.10-150300.4.30.1"],"introduced":["0"],"last_affected":[],"package":"python-urllib3","purl":"pkg:rpm/suse/python-urllib3\u0026distro=SUSE%20Linux%20Enterprise%20Server%2015%20SP6-LTSS","source":"SUSE-SU-2026:2854-2"},{"ecosystem":"SUSE:Linux Enterprise Server for SAP Applications 15 SP4","fixed":["1.25.10-150300.4.30.1"],"introduced":["0"],"last_affected":[],"package":"python-urllib3","purl":"pkg:rpm/suse/python-urllib3\u0026distro=SUSE%20Linux%20Enterprise%20Server%20for%20SAP%20Applications%2015%20SP4","source":"SUSE-SU-2026:2854-2"},{"ecosystem":"SUSE:Linux Enterprise Server for SAP Applications 15 SP5","fixed":["1.25.10-150300.4.30.1"],"introduced":["0"],"last_affected":[],"package":"python-urllib3","purl":"pkg:rpm/suse/python-urllib3\u0026distro=SUSE%20Linux%20Enterprise%20Server%20for%20SAP%20Applications%2015%20SP5","source":"SUSE-SU-2026:2854-2"},{"ecosystem":"SUSE:Linux Enterprise Server for SAP Applications 15 SP6","fixed":["1.25.10-150300.4.30.1"],"introduced":["0"],"last_affected":[],"package":"python-urllib3","purl":"pkg:rpm/suse/python-urllib3\u0026distro=SUSE%20Linux%20Enterprise%20Server%20for%20SAP%20Applications%2015%20SP6","source":"SUSE-SU-2026:2854-2"}],"prev":{"headline":"NiceGUI Stored/Reflected XSS in ui.interactive_image via unsanitized SVG content","id":"CVE-2025-66470"},"products":["urllib3"],"published":"2025-12-05","related":[{"cvss_score":8.9,"headline":"urllib3: HTTPResponse.stream()/read_chunked() buffers an unbounded chunk-size line into memory","id":"CVE-2026-97689","kev_date_added":null,"published":"2026-09-29"},{"cvss_score":8.9,"headline":"urllib3: Decompression-bomb safeguards bypassed in parts of the streaming API","id":"CVE-2026-44432","kev_date_added":null,"published":"2026-05-13"},{"cvss_score":8.9,"headline":"urllib3 vulnerable to decompression-bomb safeguard bypass when following HTTP redirects (streaming API)","id":"CVE-2026-21441","kev_date_added":null,"published":"2026-01-07"},{"cvss_score":8.9,"headline":"urllib3 allows an unbounded number of links in the decompression chain","id":"CVE-2025-66418","kev_date_added":null,"published":"2025-12-05"},{"cvss_score":8.2,"headline":"urllib3: Sensitive headers forwarded across origins in proxied low-level redirects","id":"CVE-2026-44431","kev_date_added":null,"published":"2026-05-13"},{"cvss_score":7.6,"headline":"urllib3: HTTPS proxy TLS configuration may be ignored or overridden","id":"CVE-2026-97687","kev_date_added":null,"published":"2026-09-29"}],"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":"CC BY 4.0","name":"Red Hat","prefix":"RHSA"},{"class":"attribution","licence":"CC BY 4.0","name":"SUSE","prefix":"SUSE"},{"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)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2025-12-05","vendors":["urllib3"]},"summary":"Attackers can cause excessive CPU and memory consumption in urllib3 by sending highly compressed data, leading to denial of service.","url":"https://insights.sbomify.com/CVE-2025-66471/"}