{"cve":{"cve_id":"CVE-2024-12254","is_kev":false,"kev_date_added":null,"kev_vendor_project":null,"kev_product":null,"kev_vulnerability_name":null,"kev_short_description":null,"kev_required_action":null,"kev_due_date":null,"kev_known_ransomware":null,"kev_notes":null,"kev_cwes":null,"epss_score":0.01844,"epss_percentile":0.76256,"epss_as_of":"2026-06-23","description":"Starting in Python 3.12.0, the asyncio._SelectorSocketTransport.writelines()\n method would not \"pause\" writing and signal to the Protocol to drain \nthe buffer to the wire once the write buffer reached the \"high-water \nmark\". Because of this, Protocols would not periodically drain the write\n buffer potentially leading to memory exhaustion.\n\n\n\n\n\nThis\n vulnerability likely impacts a small number of users, you must be using\n Python 3.12.0 or later, on macOS or Linux, using the asyncio module \nwith protocols, and using .writelines() method which had new \nzero-copy-on-write behavior in Python 3.12.0 and later. If not all of \nthese factors are true then your usage of Python is unaffected.","published_at":"2024-12-06T15:19:41.576000Z","last_modified_at":null,"cvss_v3_score":7.5,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvss_v3_severity":"HIGH","cvss_v4_score":8.7,"cvss_v4_vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","cvss_v4_severity":"HIGH","ssvc_decision":null,"ssvc_exploitation":"none","ssvc_automatable":true,"ssvc_technical_impact":"partial","cwes":["CWE-400","CWE-770"],"nvd_references":["https://github.com/python/cpython/issues/127655","https://github.com/python/cpython/pull/127656","https://mail.python.org/archives/list/security-announce@python.org/thread/H4O3UBAOAQQXGT4RE3E4XQYR5XLROORB/","https://github.com/python/cpython/commit/71e8429ac8e2adc10084ab5ec29a62f4b6671a82","https://github.com/python/cpython/commit/9aa0deb2eef2655a1029ba228527b152353135b5","https://github.com/python/cpython/commit/e991ac8f2037d78140e417cc9a9486223eb3e786"],"vuln_status":null,"trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-06-24T00:09:39.878444Z","updated_at":"2026-06-29T01:50:23.278006Z"},"effective_severity":"HIGH","badges":[],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"PR","name":"Privileges Required","value":"N","value_label":"None"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"U","value_label":"Unchanged"},{"metric":"C","name":"Confidentiality","value":"N","value_label":"None"},{"metric":"I","name":"Integrity","value":"N","value_label":"None"},{"metric":"A","name":"Availability","value":"H","value_label":"High"}]},"cvss_v4_decoded":{"version":"4.0","metrics":[{"metric":"AV","name":"Attack Vector","value":"N","value_label":"Network"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"AT","name":"Attack Requirements","value":"N","value_label":"None"},{"metric":"PR","name":"Privileges Required","value":"N","value_label":"None"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"VC","name":"Confidentiality (Vulnerable System)","value":"N","value_label":"None"},{"metric":"VI","name":"Integrity (Vulnerable System)","value":"N","value_label":"None"},{"metric":"VA","name":"Availability (Vulnerable System)","value":"H","value_label":"High"},{"metric":"SC","name":"Confidentiality (Subsequent System)","value":"N","value_label":"None"},{"metric":"SI","name":"Integrity (Subsequent System)","value":"N","value_label":"None"},{"metric":"SA","name":"Availability (Subsequent System)","value":"N","value_label":"None"}]},"affected":[{"vendor_slug":"python-software-foundation","vendor_name":"Python Software Foundation","product_slug":"cpython","product_name":"CPython","version_start":"3.12.0","version_start_inclusive":true,"version_end":"3.12.9","version_end_inclusive":false,"cpe23_uri":"cve5:python-software-foundation:cpython:3.12.0:3.12.9"},{"vendor_slug":"python-software-foundation","vendor_name":"Python Software Foundation","product_slug":"cpython","product_name":"CPython","version_start":"3.13.0","version_start_inclusive":true,"version_end":"3.13.2","version_end_inclusive":false,"cpe23_uri":"cve5:python-software-foundation:cpython:3.13.0:3.13.2"},{"vendor_slug":"python-software-foundation","vendor_name":"Python Software Foundation","product_slug":"cpython","product_name":"CPython","version_start":"3.14.0a1","version_start_inclusive":true,"version_end":"3.14.0a3","version_end_inclusive":false,"cpe23_uri":"cve5:python-software-foundation:cpython:3.14.0a1:3.14.0a3"}],"exploit_refs":[],"news":[],"references":[{"url":"https://github.com/python/cpython/issues/127655","source_type":"MISC","tags":[]},{"url":"https://github.com/python/cpython/pull/127656","source_type":"PATCH","tags":["patch"]},{"url":"https://mail.python.org/archives/list/security-announce@python.org/thread/H4O3UBAOAQQXGT4RE3E4XQYR5XLROORB/","source_type":"MISC","tags":[]},{"url":"https://github.com/python/cpython/commit/71e8429ac8e2adc10084ab5ec29a62f4b6671a82","source_type":"PATCH","tags":["patch"]},{"url":"https://github.com/python/cpython/commit/9aa0deb2eef2655a1029ba228527b152353135b5","source_type":"PATCH","tags":["patch"]},{"url":"https://github.com/python/cpython/commit/e991ac8f2037d78140e417cc9a9486223eb3e786","source_type":"PATCH","tags":["patch"]}],"timeline":[{"type":"published","at":"2024-12-06T15:19:41.576000Z","label":"CVE 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