{"cve":{"cve_id":"CVE-2023-4039","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":0.00666,"epss_percentile":0.46973,"epss_as_of":"2026-06-23","description":"**DISPUTED**A failure in the -fstack-protector feature in GCC-based toolchains \nthat target AArch64 allows an attacker to exploit an existing buffer \noverflow in dynamically-sized local variables in your application \nwithout this being detected. This stack-protector failure only applies \nto C99-style dynamically-sized local variables or those created using \nalloca(). The stack-protector operates as intended for statically-sized \nlocal variables.\n\nThe default behavior when the stack-protector \ndetects an overflow is to terminate your application, resulting in \ncontrolled loss of availability. An attacker who can exploit a buffer \noverflow without triggering the stack-protector might be able to change \nprogram flow control to cause an uncontrolled loss of availability or to\n go further and affect confidentiality or integrity. NOTE: The GCC project argues that this is a missed hardening bug and not a vulnerability by itself.","published_at":"2023-09-13T08:05:10.274000Z","last_modified_at":null,"cvss_v3_score":4.8,"cvss_v3_vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","cvss_v3_severity":"MEDIUM","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":"poc","ssvc_automatable":false,"ssvc_technical_impact":"partial","cwes":["CWE-693"],"nvd_references":["https://developer.arm.com/Arm%20Security%20Center/GCC%20Stack%20Protector%20Vulnerability%20AArch64","https://github.com/metaredteam/external-disclosures/security/advisories/GHSA-x7ch-h5rf-w2mf"],"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":"2026-06-29T01:41:16.128405Z"},"effective_severity":"MEDIUM","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":"H","value_label":"High"},{"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":"L","value_label":"Low"},{"metric":"I","name":"Integrity","value":"L","value_label":"Low"},{"metric":"A","name":"Availability","value":"N","value_label":"None"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"arm-ltd","vendor_name":"Arm Ltd","product_slug":"arm-gnu-toolchain","product_name":"Arm GNU Toolchain","version_start":"All versions where option -fstack-protector is used","version_start_inclusive":true,"version_end":"All versions where option -fstack-protector is used","version_end_inclusive":true,"cpe23_uri":"cve5:arm-ltd:arm-gnu-toolchain:All versions where option -fstack-protector is used:All versions where option -fstack-protector is used"},{"vendor_slug":"gnu","vendor_name":"gnu","product_slug":"gcc","product_name":"GCC","version_start":"All versions of GCC that target AArch64 when option -fstack-protector is used","version_start_inclusive":true,"version_end":"All versions of GCC that target AArch64 when option -fstack-protector is used","version_end_inclusive":true,"cpe23_uri":"cve5:gnu:gcc:All versions of GCC that target AArch64 when option -fstack-protector is used:All versions of GCC that target AArch64 when option -fstack-protector is used"}],"exploit_refs":[],"news":[],"references":[{"url":"https://developer.arm.com/Arm%20Security%20Center/GCC%20Stack%20Protector%20Vulnerability%20AArch64","source_type":"MISC","tags":[]},{"url":"https://github.com/metaredteam/external-disclosures/security/advisories/GHSA-x7ch-h5rf-w2mf","source_type":"VENDOR_ADVISORY","tags":["advisory"]}],"timeline":[{"type":"published","at":"2023-09-13T08:05:10.274000Z","label":"CVE published","source":null},{"type":"cvss_changed","at":"2026-06-28T17:30:45.033233Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:30:45.033233Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:30:45.033233Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"ssvc_changed","at":"2026-06-29T01:41:16.128405Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-06-29T01:41:16.128405Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-06-29T01:41:16.128405Z","label":"SSVC decision revised","source":"vulnrichment"}]}