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vuln-cve/data/2026/90xxx/CVE-2026-90833.json
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{
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"cveMetadata": {
"cveId": "CVE-2026-90833",
"assignerOrgId": "e2e69745-5e70-4e92-8431-deb5529a81ad",
"state": "PUBLISHED",
"assignerShortName": "zephyr",
"dateReserved": "2026-09-13T19:22:58.656Z",
"datePublished": "2026-11-10T22:07:42.603Z",
"dateUpdated": "2026-11-13T13:36:52.612Z"
},
"containers": {
"cna": {
"providerMetadata": {
"orgId": "e2e69745-5e70-4e92-8431-deb5529a81ad",
"shortName": "zephyr",
"dateUpdated": "2026-11-10T22:07:42.603Z"
},
"title": "Signed offset bypasses bounds check in simulated EEPROM driver, allowing out-of-bounds kernel memory read and write from user mode",
"descriptions": [
{
"lang": "en",
"value": "The simulated EEPROM driver validated access ranges in eeprom_range_is_valid() (drivers/eeprom/eeprom_simulator.c) with a single test, (offset + len) <= config->size. Because offset is a signed off_t and len an unsigned size_t of the same rank, the addition is evaluated in unsigned arithmetic: a negative offset combined with a compensating len wraps the sum back into the accepted range. eeprom_sim_read() and eeprom_sim_write() then memcpy() through the EEPROM(addr) macro, which is plain pointer arithmetic on the driver's static mock_eeprom array, so the copy addresses memory located before that array.\n\neeprom_read() and eeprom_write() are __syscall entry points, and their verification handlers in drivers/eeprom/eeprom_handlers.c check only the device object and the caller's own data buffer (K_SYSCALL_MEMORY_READ/K_SYSCALL_MEMORY_WRITE) — the offset argument is passed to the driver unvalidated. With CONFIG_USERSPACE=y, a CONFIG_EEPROM_SIMULATOR device instance, and the device object granted to a user thread (the usage the in-tree tests/drivers/eeprom/api suite exercises from ZTEST_USER threads), an unprivileged thread could supply a negative offset and have the kernel perform the copy on its behalf.\n\nThe result is an out-of-bounds read of kernel .bss returned into the caller's buffer and, via the write path, an out-of-bounds write of caller-supplied bytes over kernel memory preceding mock_eeprom. Both the start address and the length of the affected span are attacker-selected, so the primitive is sufficient to corrupt adjacent kernel state and escape the user-mode sandbox. Exposure is limited to builds that instantiate the simulated EEPROM (status = \"okay\" by default on qemu_x86 and native_sim, otherwise added by a devicetree overlay) together with userspace isolation.\n\nThe fix rejects negative offsets and performs the remaining bound check without overflow."
}
],
"affected": [
{
"vendor": "zephyrproject",
"product": "zephyr",
"collectionURL": "https://github.com/zephyrproject-rtos/zephyr",
"packageName": "zephyr",
"defaultStatus": "unaffected",
"programFiles": [
"drivers/eeprom/eeprom_simulator.c"
],
"programRoutines": [
{
"name": "eeprom_range_is_valid"
},
{
"name": "eeprom_sim_read"
},
{
"name": "eeprom_sim_write"
},
{
"name": "z_vrfy_eeprom_read"
},
{
"name": "z_vrfy_eeprom_write"
}
],
"versions": [
{
"version": "2.2.0",
"status": "affected",
"versionType": "semver",
"lessThan": "4.3.2"
},
{
"version": "4.4.0",
"status": "affected",
"versionType": "semver",
"lessThan": "4.5.0"
}
]
}
],
"references": [
{
"url": "https://github.com/zephyrproject-rtos/zephyr/commit/ce2ec9b3a34d71f52f5d1d7491b91393e334713e",
"name": "Fix commit",
"tags": [
"patch"
]
},
{
"url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-vf6j-hcx8-44vh",
"name": "GHSA-vf6j-hcx8-44vh"
}
],
"metrics": [
{
"format": "CVSS",
"cvssV3_1": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"baseScore": 7.8,
"baseSeverity": "HIGH"
}
}
],
"problemTypes": [
{
"descriptions": [
{
"lang": "en",
"description": "bounds",
"cweId": "CWE-787",
"type": "CWE"
}
]
}
],
"x_generator": {
"engine": "cvelib 1.8.0"
}
},
"adp": [
{
"metrics": [
{
"other": {
"type": "ssvc",
"content": {
"timestamp": "2026-11-13T13:36:31.771160Z",
"id": "CVE-2026-90833",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "no"
},
{
"Technical Impact": "total"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
}
],
"title": "CISA ADP Vulnrichment",
"providerMetadata": {
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP",
"dateUpdated": "2026-11-13T13:36:52.612Z"
}
}
]
}
}