CVE-2026-23787: Samsung Exynos DPU Use-After-Free Vulnerability

CVE-2026-23787 Overview

CVE-2026-23787 is a use-after-free vulnerability [CWE-416] in the Display Processing Unit (DPU) component of multiple Samsung Mobile Processor Exynos chipsets. The flaw resides in the Exynos Direct Rendering Manager (DRM) High Dynamic Range (HDR) driver. Improper cleanup after a vmap failure leaves a dangling kernel reference that a local attacker can trigger to cause a kernel crash. Exploitation requires local access and low privileges, and no user interaction is needed. Samsung published details through its semiconductor product security update program.

Critical Impact
A local, low-privileged process can trigger a kernel crash by inducing a vmap failure path in the Exynos DRM HDR driver, resulting in denial of service on affected Samsung Exynos-based mobile devices.

Affected Products

Samsung Mobile Processor Exynos 1280, 1380, 1480, 1580, 1680
Samsung Mobile Processor Exynos 2200, 2400, 2500, 2600
Devices shipping the Exynos DRM HDR kernel driver in the DPU subsystem

Discovery Timeline

2026-09-14 - CVE-2026-23787 published to NVD
2026-09-14 - Last updated in NVD database

Technical Details for CVE-2026-23787

Vulnerability Analysis

The vulnerability affects the HDR driver inside the Exynos DRM stack, which is part of the DPU subsystem that composites and renders display buffers. The kernel path allocates a resource and maps it into virtual address space using vmap. When the vmap call fails, the error-handling path does not correctly release or invalidate all associated references. A subsequent code path then dereferences memory that has already been freed, producing a use-after-free condition. The result is memory corruption inside kernel context, which reliably crashes the kernel. The issue is scoped to local attackers who can invoke the affected DRM ioctl or rendering path from userspace.

Root Cause

The root cause is improper cleanup on an error path. When vmap fails inside the Exynos DRM HDR driver, the driver releases an underlying object without clearing pointers that reference it. Later access through those stale pointers dereferences freed memory, matching the classic CWE-416 pattern.

Attack Vector

A local process with permission to interact with the DRM device node triggers the vulnerable path by issuing HDR-related ioctls under conditions that force a vmap allocation failure. High attack complexity reflects the need to reliably induce the failure state and race the freed reference. Successful triggering causes a kernel panic and device reboot.

No verified proof-of-concept code has been published. See the Samsung CVE-2026-23787 advisory for vendor technical details.

Detection Methods for CVE-2026-23787

Indicators of Compromise

Unexpected kernel panics referencing the Exynos DRM HDR driver or vmap-related call stacks in dmesg or logcat kernel logs.
Repeated device reboots correlated with the launch of a specific application accessing DRM device nodes such as /dev/dri/*.
Crash dumps containing use-after-free signatures in DPU or HDR driver symbols.

Detection Strategies

Enable Kernel Address Sanitizer (KASAN) on test builds to identify use-after-free accesses in the Exynos DRM HDR driver.
Monitor Android bugreport archives and vendor RIL logs for repeated SIGSEGV events tied to graphics processes.
Review mobile device management (MDM) telemetry for elevated crash rates on Exynos-based device fleets.

Monitoring Recommendations

Ingest mobile device crash and reboot events into a central analytics pipeline for baseline comparison.
Alert on statistically abnormal kernel crash rates for a single application across a device fleet.
Track patch level compliance for Samsung security bulletins across managed Exynos-based devices.

How to Mitigate CVE-2026-23787

Immediate Actions Required

Apply the Samsung security update that includes the fix for the Exynos DRM HDR driver as soon as it is delivered by the device OEM.
Inventory managed mobile devices to identify Exynos 1280, 1380, 1480, 1580, 1680, 2200, 2400, 2500, and 2600 chipsets.
Restrict installation of untrusted applications that could exercise the vulnerable DRM code path.

Patch Information

Samsung has published the fix through its semiconductor product security update program. Refer to the Samsung Product Security Updates portal and the CVE-2026-23787 advisory page for firmware versions and device-vendor integration guidance. End users should install the corresponding monthly Samsung Mobile security update from their device manufacturer.

Workarounds

Enforce MDM policies that block sideloading and restrict application installs to vetted sources.
Limit access to graphics DRM interfaces for untrusted workloads on affected devices where technically feasible.
Monitor for kernel crash telemetry and quarantine devices exhibiting repeated Exynos DPU-related panics until patched.

bash

# Example: check Android build and security patch level on an affected device
adb shell getprop ro.build.version.release
adb shell getprop ro.build.version.security_patch
adb shell getprop ro.soc.model