Is CVE-2026-19737 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-19737 being exploited in the wild.

How severe is CVE-2026-19737?

Medium severity, with a CVSS score of 5.5, published 11 October 2026.

Which products and versions are affected?

Zephyr OS v4.4.0 and later (userspace-enabled builds with RISC-V PMP on ESP32-C6 or ESP32-C5).

How is CVE-2026-19737 attacked?

It is attacked with local access, in an operating system.

Am I affected by CVE-2026-19737?

Check whether you run Zephyr OS at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-19737: Zephyr i2s_esp32 null pointer dereference in trigger validation

CVE-2026-19737 · Severity: medium · CVSS 5.5 · Published 2026-10-11

Zephyr's ESP32 I2S driver incorrectly validates the direction parameter in trigger operations, allowing a user-mode thread with I2S device access to cause a null pointer read in kernel mode. On systems with userspace enabled, this can crash the entire system. The vulnerability is limited to denial of service; there is no data exposure or code execution risk.

Technologies: Zephyr OS. Vendors: Zephyr.

Quick answers

Is CVE-2026-19737 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-19737 being exploited in the wild.
How severe is CVE-2026-19737?: Medium severity, with a CVSS score of 5.5, published 11 October 2026.
Which products and versions are affected?: Zephyr OS v4.4.0 and later (userspace-enabled builds with RISC-V PMP on ESP32-C6 or ESP32-C5).
Is there a fix for CVE-2026-19737?: No fixed version is recorded yet. Disable CONFIG_USERSPACE on affected Espressif platforms, or restrict I2S device permissions to trusted kernel code only. The fix validates stream pointers for all direction values before dereferencing them.</anigation> <parameter name="fixed_in">Zephyr v4.4.1 and later; backported to v4.3-branch If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-19737 attacked?: It is attacked with local access, in an operating system.
Am I affected by CVE-2026-19737?: Check whether you run Zephyr OS at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Disable CONFIG_USERSPACE on affected Espressif platforms, or restrict I2S device permissions to trusted kernel code only. The fix validates stream pointers for all direction values before dereferencing them.</anigation> <parameter name="fixed_in">Zephyr v4.4.1 and later; backported to v4.3-branch

Technical details

The i2s_esp32_trigger_check() function in drivers/i2s/i2s_esp32.c fails to validate stream pointers when the I2S_DIR_RX or I2S_DIR_TX direction is specified, only performing the check for I2S_DIR_BOTH. On single-direction I2S instances, this leads to a read from address 0 when an unwanted direction is triggered. The vulnerability is reachable via the i2s_trigger() syscall on userspace-enabled builds (CONFIG_USERSPACE) where an unprivileged thread with I2S device permissions can trigger the dereference, causing a fatal exception in kernel mode.

Affected products

Zephyr Zephyr OS v4.4.0 and later (userspace-enabled builds with RISC-V PMP on ESP32-C6 or ESP32-C5)

Timeline

2026-10-11: disclosed

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