{"id":"CVE-2023-40548","title":"A buffer overflow was found in Shim in the 32-bit system","summary":"A buffer overflow was found in Shim in the 32-bit system. The overflow happens due to an addition operation involving a user-controlled value parsed from the PE binary being used by Shim. This value is further used for memory allocation …","severity":"high","cvss":7.4,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-190","CWE-190","CWE-787"],"vendor":"redhat","product":"shim","affected":["shim < 15.8","shim = 15.8","fedora = 39"],"patched":["shim 15.8"],"published":"2024-01-29","updated":"2026-06-26","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2023-40548","references":[{"url":"https://access.redhat.com/errata/RHSA-2024:1834","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2024:1835","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2024:1873","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2024:1876","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2024:1883","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2024:1902","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2024:1903","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2024:1959","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2024:2086","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/security/cve/CVE-2023-40548","label":"secalert@redhat.com"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2241782","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2024:1834","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2024:1835","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2024:1873","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2024:1876","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2024:1883","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2024:1902","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2024:1903","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2024:1959","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2024:2086","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/security/cve/CVE-2023-40548","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2241782","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2024/05/msg00009.html","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd"],"epss":0.00436,"epssPercentile":0.37214,"ingestedAt":"2026-06-26T16:43:13.377Z","slug":"CVE-2023-40548","body":"## Overview\n\nA buffer overflow was found in Shim in the 32-bit system. The overflow happens due to an addition operation involving a user-controlled value parsed from the PE binary being used by Shim. This value is further used for memory allocation operations, leading to a heap-based buffer overflow. This flaw causes memory corruption and can lead to a crash or data integrity issues during the boot phase.\n\n## Affected\n\n- `shim < 15.8`\n- `shim = 15.8`\n- `fedora = 39`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `shim 15.8`","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":40.7,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}