CVE-2026-11743
Missing negative-offset/overflow check in SF32LB MPI QSPI NOR flash driver allows out-of-bounds read and write
Description
The SF32LB MPI QSPI NOR flash driver (drivers/flash/flash_sf32lb_mpi_qspi_nor.c) validated the flash offset and length on its read and write paths with the test (offset + size) > data->size. Because offset is a signed off_t while size is unsigned, a negative offset is converted to a large unsigned value and the addition can wrap to a small result that passes the check. The read path then performs memcpy(dst, (void *)(data->base + offset), size) and the write path programs flash at offset and cache-invalidates data->base + offset, in both cases accessing memory outside the mapped flash window. The driver's erase path already rejected negative offsets, but read and write did not. In builds with CONFIG_USERSPACE, flash_read and flash_write are syscalls whose verifiers validate the device object and the caller's buffer but deliberately delegate offset bounds checking to the driver. An unprivileged thread that has been granted access to this flash device can therefore call the syscall with a crafted negative offset and a buffer valid in its own memory domain, and reach the unchecked access. The most direct impact is on the read path: by choosing a negative offset and matching size, an attacker slides the memcpy source below the flash base and copies arbitrary CPU-addressable memory into its own buffer, disclosing memory it is not authorized to read. The write path additionally allows programming flash at an out-of-range address and invalidating an attacker-chosen cache range, affecting integrity and availability. Reachability requires userspace to be enabled and the raw flash device object to be granted to an untrusted thread. The fix replaces the check with qspi_nor_range_is_valid(), which rejects negative offsets and performs the bound comparison in overflow-safe 64-bit arithmetic on both paths, and additionally adds an SRAM DMA bounce buffer plus source/destination overlap rejection to prevent a separate DMA bus-hang condition.
INFO
Published Date :
Aug. 7, 2026, 10:16 p.m.
Last Modified :
Aug. 7, 2026, 10:16 p.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-11743
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | e2e69745-5e70-4e92-8431-deb5529a81ad | ||||
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update the SF32LB MPI QSPI NOR flash driver.
- Ensure offset and size checks prevent wrap-around.
- Implement overflow-safe 64-bit arithmetic checks.
- Add SRAM DMA bounce buffer and overlap rejection.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-11743.
| URL | Resource |
|---|---|
| https://github.com/zephyrproject-rtos/zephyr/commit/909eb568750304d68ea481d1b56a489ae670bdae | |
| https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-c6wh-gwg4-fj5j |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-11743 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-11743
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-11743 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-11743 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Aug. 07, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'zephyrproject', 'product': 'zephyr', 'versions': [{'status': 'affected', 'version': '4.3.0', 'lessThan': '4.4.2', 'versionType': 'semver'}], 'packageName': 'zephyr', 'programFiles': ['drivers/flash/flash_sf32lb_mpi_qspi_nor.c'], 'collectionURL': 'https://github.com/zephyrproject-rtos/zephyr', 'defaultStatus': 'unaffected'}] Added Description The SF32LB MPI QSPI NOR flash driver (drivers/flash/flash_sf32lb_mpi_qspi_nor.c) validated the flash offset and length on its read and write paths with the test (offset + size) > data->size. Because offset is a signed off_t while size is unsigned, a negative offset is converted to a large unsigned value and the addition can wrap to a small result that passes the check. The read path then performs memcpy(dst, (void *)(data->base + offset), size) and the write path programs flash at offset and cache-invalidates data->base + offset, in both cases accessing memory outside the mapped flash window. The driver's erase path already rejected negative offsets, but read and write did not. In builds with CONFIG_USERSPACE, flash_read and flash_write are syscalls whose verifiers validate the device object and the caller's buffer but deliberately delegate offset bounds checking to the driver. An unprivileged thread that has been granted access to this flash device can therefore call the syscall with a crafted negative offset and a buffer valid in its own memory domain, and reach the unchecked access. The most direct impact is on the read path: by choosing a negative offset and matching size, an attacker slides the memcpy source below the flash base and copies arbitrary CPU-addressable memory into its own buffer, disclosing memory it is not authorized to read. The write path additionally allows programming flash at an out-of-range address and invalidating an attacker-chosen cache range, affecting integrity and availability. Reachability requires userspace to be enabled and the raw flash device object to be granted to an untrusted thread. The fix replaces the check with qspi_nor_range_is_valid(), which rejects negative offsets and performs the bound comparison in overflow-safe 64-bit arithmetic on both paths, and additionally adds an SRAM DMA bounce buffer plus source/destination overlap rejection to prevent a separate DMA bus-hang condition. Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L Added CWE CWE-125 Added Reference https://github.com/zephyrproject-rtos/zephyr/commit/909eb568750304d68ea481d1b56a489ae670bdae Added Reference https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-c6wh-gwg4-fj5j