{ "document": { "aggregate_severity": { "text": "Important" }, "category": "csaf_security_advisory", "csaf_version": "2.0", "distribution": { "text": "TuxCare License Agreement", "tlp": { "label": "WHITE", "url": "https://www.first.org/tlp/" } }, "lang": "en", "notes": [ { "category": "legal_disclaimer", "text": "This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Cloud Linux Inc. and provide a link to the original.", "title": "Terms of Use" }, { "category": "details", "text": "CVE-2025-66471: fix improper handling of highly compressed data in the\n Streaming API", "title": "Details" } ], "publisher": { "category": "vendor", "contact_details": "https://tuxcare.com/contact/", "name": "TuxCare", "namespace": "https://tuxcare.com/" }, "references": [ { "category": "self", "summary": "Canonical URL", "url": "https://security.tuxcare.com/csaf/v2/els_os/almalinux9.2esu/advisories/2026/clsa-2026_1770035896.json" }, { "category": "self", "summary": "https://cve.tuxcare.com/els/releases/CLSA-2026:1770035896", "url": "https://cve.tuxcare.com/els/releases/CLSA-2026:1770035896" } ], "tracking": { "current_release_date": "2026-02-16T10:02:56Z", "generator": { "date": "2026-02-16T10:02:56Z", "engine": { "name": "pyCSAF" } }, "id": "CLSA-2026:1770035896", "initial_release_date": "2026-02-02T13:34:05Z", "revision_history": [ { "date": "2026-02-02T13:34:05Z", "number": "1", "summary": "Initial version" }, { "date": "2026-02-16T10:02:56Z", "number": "2", "summary": "Update document" } ], "status": "final", "version": "2" }, "title": "python3.11-urllib3: Fix of CVE-2025-66471" }, "product_tree": { "branches": [ { "branches": [ { "branches": [ { "category": "product_name", "name": "AlmaLinux 9.2", "product": { "name": "AlmaLinux 9.2", "product_id": "AlmaLinux-9.2", "product_identification_helper": { "cpe": "cpe:2.3:o:almalinux:almalinux:9.2:*:*:*:*:*:*:*" } } } ], "category": "product_family", "name": "AlmaLinux" } ], "category": "vendor", "name": "AlmaLinux OS Foundation" }, { "branches": [ { "branches": [ { "category": "product_version", "name": "python3.11-urllib3-0:1.26.12-5.el9.tuxcare.els2.noarch", "product": { "name": "python3.11-urllib3-0:1.26.12-5.el9.tuxcare.els2.noarch", "product_id": "python3.11-urllib3-0:1.26.12-5.el9.tuxcare.els2.noarch", "product_identification_helper": { "purl": "pkg:rpm/tuxcare/python3.11-urllib3@1.26.12-5.el9.tuxcare.els2?arch=noarch" } } } ], "category": "architecture", "name": "noarch" } ], "category": "vendor", "name": "TuxCare" } ], "relationships": [ { "category": "default_component_of", "full_product_name": { "name": "python3.11-urllib3-0:1.26.12-5.el9.tuxcare.els2.noarch as a component of AlmaLinux 9.2", "product_id": "AlmaLinux-9.2:python3.11-urllib3-0:1.26.12-5.el9.tuxcare.els2.noarch" }, "product_reference": "python3.11-urllib3-0:1.26.12-5.el9.tuxcare.els2.noarch", "relates_to_product_reference": "AlmaLinux-9.2" } ] }, "vulnerabilities": [ { "cve": "CVE-2025-66471", "cwe": { "id": "CWE-409", "name": "Improper Handling of Highly Compressed Data (Data Amplification)" }, "notes": [ { "category": "description", "text": "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.", "title": "Vulnerability description" }, { "category": "general", "text": "The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.", "title": "CVSS score applicability" } ], "product_status": { "fixed": [ "AlmaLinux-9.2:python3.11-urllib3-0:1.26.12-5.el9.tuxcare.els2.noarch" ] }, "references": [ { "category": "self", "summary": "Canonical URL", "url": "https://cve.tuxcare.com/els/cve/CVE-2025-66471" }, { "category": "external", "summary": "https://github.com/urllib3/urllib3/commit/c19571de34c47de3a766541b041637ba5f716ed7", "url": "https://github.com/urllib3/urllib3/commit/c19571de34c47de3a766541b041637ba5f716ed7" }, { "category": "external", "summary": "https://github.com/urllib3/urllib3/security/advisories/GHSA-2xpw-w6gg-jr37", "url": "https://github.com/urllib3/urllib3/security/advisories/GHSA-2xpw-w6gg-jr37" } ], "release_date": "2025-12-05T17:16:00Z", "remediations": [ { "category": "vendor_fix", "date": "2026-02-02T12:38:18.112844Z", "details": "Details on how to apply the fix are available at: https://cve.tuxcare.com/els/releases/CLSA-2026:1770035896", "product_ids": [ "AlmaLinux-9.2:python3.11-urllib3-0:1.26.12-5.el9.tuxcare.els2.noarch" ], "url": "https://cve.tuxcare.com/els/releases/CLSA-2026:1770035896" } ], "scores": [ { "cvss_v3": { "attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1" }, "products": [ "AlmaLinux-9.2:python3.11-urllib3-0:1.26.12-5.el9.tuxcare.els2.noarch" ] } ], "threats": [ { "category": "impact", "details": "Important" } ] }, { "cve": "CVE-2025-66418", "cwe": { "id": "CWE-770", "name": "Allocation of Resources Without Limits or Throttling" }, "notes": [ { "category": "description", "text": "urllib3 is a user-friendly HTTP client library for Python. Starting in version 1.24 and prior to 2.6.0, the number of links in the decompression chain was unbounded allowing a malicious server to insert a virtually unlimited number of compression steps leading to high CPU usage and massive memory allocation for the decompressed data. This vulnerability is fixed in 2.6.0.", "title": "Vulnerability description" }, { "category": "general", "text": "The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.", "title": "CVSS score applicability" } ], "product_status": { "fixed": [ "AlmaLinux-9.2:python3.11-urllib3-0:1.26.12-5.el9.tuxcare.els2.noarch" ] }, "references": [ { "category": "self", "summary": "Canonical URL", "url": "https://cve.tuxcare.com/els/cve/CVE-2025-66418" }, { "category": "external", "summary": "https://github.com/urllib3/urllib3/commit/24d7b67eac89f94e11003424bcf0d8f7b72222a8", "url": "https://github.com/urllib3/urllib3/commit/24d7b67eac89f94e11003424bcf0d8f7b72222a8" }, { "category": "external", "summary": "https://github.com/urllib3/urllib3/security/advisories/GHSA-gm62-xv2j-4w53", "url": "https://github.com/urllib3/urllib3/security/advisories/GHSA-gm62-xv2j-4w53" } ], "release_date": "2025-12-05T16:15:00Z", "remediations": [ { "category": "vendor_fix", "date": "2026-02-02T12:38:18.112844Z", "details": "Details on how to apply the fix are available at: https://cve.tuxcare.com/els/releases/CLSA-2026:1770035896", "product_ids": [ "AlmaLinux-9.2:python3.11-urllib3-0:1.26.12-5.el9.tuxcare.els2.noarch" ], "url": "https://cve.tuxcare.com/els/releases/CLSA-2026:1770035896" } ], "scores": [ { "cvss_v3": { "attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1" }, "products": [ "AlmaLinux-9.2:python3.11-urllib3-0:1.26.12-5.el9.tuxcare.els2.noarch" ] } ], "threats": [ { "category": "impact", "details": "Important" } ] }, { "cve": "CVE-2026-21441", "cwe": { "id": "CWE-409", "name": "Improper Handling of Highly Compressed Data (Data Amplification)" }, "notes": [ { "category": "description", "text": "urllib3 is an HTTP client library for Python. 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. urllib3 can perform decoding or decompression based on the HTTP `Content-Encoding` header (e.g., `gzip`, `deflate`, `br`, or `zstd`). When using the streaming API, the library decompresses only the necessary bytes, enabling partial content consumption. Starting in version 1.22 and prior to version 2.6.3, for HTTP redirect responses, the library would read the entire response body to drain the connection and decompress the content unnecessarily. This decompression occurred even before any read methods were called, and configured read limits did not restrict the amount of decompressed data. As a result, there was no safeguard against decompression bombs. A malicious server could exploit this to trigger excessive resource consumption on the client. Applications and libraries are affected when they stream content from untrusted sources by setting `preload_content=False` when they do not disable redirects. Users should upgrade to at least urllib3 v2.6.3, in which the library does not decode content of redirect responses when `preload_content=False`. If upgrading is not immediately possible, disable redirects by setting `redirect=False` for requests to untrusted source.", "title": "Vulnerability description" }, { "category": "general", "text": "The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.", "title": "CVSS score applicability" } ], "product_status": { "fixed": [ "AlmaLinux-9.2:python3.11-urllib3-0:1.26.12-5.el9.tuxcare.els2.noarch" ] }, "references": [ { "category": "self", "summary": "Canonical URL", "url": "https://cve.tuxcare.com/els/cve/CVE-2026-21441" }, { "category": "external", "summary": "https://github.com/urllib3/urllib3/commit/8864ac407bba8607950025e0979c4c69bc7abc7b", "url": "https://github.com/urllib3/urllib3/commit/8864ac407bba8607950025e0979c4c69bc7abc7b" }, { "category": "external", "summary": "https://github.com/urllib3/urllib3/security/advisories/GHSA-38jv-5279-wg99", "url": "https://github.com/urllib3/urllib3/security/advisories/GHSA-38jv-5279-wg99" }, { "category": "external", "summary": "https://lists.debian.org/debian-lts-announce/2026/01/msg00017.html", "url": "https://lists.debian.org/debian-lts-announce/2026/01/msg00017.html" } ], "release_date": "2026-01-07T22:15:00Z", "remediations": [ { "category": "vendor_fix", "date": "2026-02-02T12:38:18.112844Z", "details": "Details on how to apply the fix are available at: https://cve.tuxcare.com/els/releases/CLSA-2026:1770035896", "product_ids": [ "AlmaLinux-9.2:python3.11-urllib3-0:1.26.12-5.el9.tuxcare.els2.noarch" ], "url": "https://cve.tuxcare.com/els/releases/CLSA-2026:1770035896" } ], "scores": [ { "cvss_v3": { "attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1" }, "products": [ "AlmaLinux-9.2:python3.11-urllib3-0:1.26.12-5.el9.tuxcare.els2.noarch" ] } ], "threats": [ { "category": "impact", "details": "Important" } ] } ] }