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Linux Kernel CVE-2026-53384

| EUVDEUVD-2026-45506 CRITICAL
Use After Free (CWE-416)
2026-07-19 Linux GHSA-8qr8-6qvc-c8x9
Information Disclosure Linux Use After Free Memory Corruption
Critical
Disputed · 9.8 Vendor: Linux
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Severity by source

Sources disagree (Medium–Critical)
Vendor (Linux) PRIMARY
9.8 CRITICAL
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
vuln.today AI
7.0 HIGH

Local hardware-specific driver bug reachable only via an uncommon probe-failure race, so AV:L/AC:H/PR:L; UAF can yield kernel info disclosure and memory corruption, so C/I/A:H.

3.1 AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
4.0 AV:L/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
SUSE
5.5 MEDIUM
AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Red Hat
7.0 MEDIUM
qualitative

vuln.today treats the vendor’s rating as authoritative. A higher third-party CVSS (e.g. CISA-ADP) is shown for transparency but does not drive the headline severity.

CVSS VectorVendor: Linux

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Lifecycle Timeline

5
Analysis Generated
Jul 20, 2026 - 18:04 vuln.today
CVSS changed
Jul 20, 2026 - 15:22 NVD
9.8 (CRITICAL)
Patch available
Jul 19, 2026 - 14:17 EUVD
CVE Published
Jul 19, 2026 - 11:59 cve.org
UNKNOWN (no severity yet)
CVE Published
Jul 19, 2026 - 11:59 cve.org
CRITICAL 9.8

DescriptionCVE.org

In the Linux kernel, the following vulnerability has been resolved:

serial: 8250_dw: unregister 8250 port if clk_notifier_register() fails

dw8250_probe() registers the 8250 port via serial8250_register_8250_port() and then, if the device has a clock, registers a clock notifier. If clk_notifier_register() fails, probe returns the error but leaves the 8250 port registered. The matching serial8250_unregister_port() lives in dw8250_remove(), which is not called when probe fails, so the port slot stays occupied until the device is rebound or the system is rebooted. The devm-allocated driver data is freed while the port still references it (via the saved private_data and serial_in/serial_out callbacks), so any access to that port slot before a rebind is a use-after-free hazard.

Unregister the port on the clk_notifier_register() error path.

AnalysisAI

Use-after-free in the Linux kernel's 8250_dw (Synopsys DesignWare) serial driver arises when dw8250_probe() fails during clk_notifier_register(): the already-registered 8250 port is left occupying its slot while its devm-allocated driver data is freed, leaving stale private_data and serial_in/serial_out callbacks that reference freed memory. The flaw affects kernels from 5.9 through the fixed stable releases and is tagged as an information-disclosure risk; there is no public exploit identified at time of analysis, and EPSS is low at 0.17% (7th percentile). Despite an NVD CVSS of 9.8, exploitation is gated by a probe-failure error path in a specific UART driver, so real-world reachability is far narrower than the score implies.

Technical ContextAI

The affected component is drivers/tty/serial/8250/8250_dw.c, the kernel driver for Synopsys DesignWare APB UARTs (widely used on ARM/embedded SoCs and some x86 platforms). During probe, serial8250_register_8250_port() installs the port and, when a clock is present, clk_notifier_register() attaches a notifier so the driver can respond to clock-rate changes. The bug is a classic error-path resource leak leading to use-after-free (CWE-416 class, though NVD lists CWE as N/A): if the notifier registration fails, probe returns an error without calling serial8250_unregister_port(), which normally only runs in dw8250_remove(). Because the driver's state was allocated with devm_* helpers, it is automatically freed when probe returns an error, but the still-registered port continues to point at that freed data via saved private_data and the serial_in/serial_out accessor callbacks - any subsequent access to the orphaned port slot dereferences freed memory. The fix adds serial8250_unregister_port() on the clk_notifier_register() failure path. Affected products per CPE are limited to cpe:2.3:a:linux:linux (the Linux kernel itself).

RemediationAI

Vendor-released patch: update to a fixed stable kernel - 6.1.177, 6.6.144, 6.12.95, 6.18.38, 7.0.14, 7.1.2, or mainline 7.2-rc1 or later - whichever matches your series, then reboot into the patched kernel. The fix simply adds serial8250_unregister_port() to the clk_notifier_register() error path; apply it via your distribution's kernel update channel or by cherry-picking the relevant stable commit from git.kernel.org (e.g., ccdf4510a3873b14e5e348cdb038717996f09fda for the matching branch). No practical runtime workaround exists because the bug lives inside driver probe, but the trigger is inherently rare (it requires clk_notifier_register() to fail during 8250_dw probe); on systems that do not use DesignWare UARTs the driver is not loaded and the code is unreachable, and where it is not needed the module can be blacklisted (side effect: loss of that serial console/port). Given low EPSS and no known exploitation, schedule this as a routine kernel maintenance update rather than an emergency patch. See https://nvd.nist.gov/vuln/detail/CVE-2026-53384 for tracking.

Same weakness CWE-416 – Use After Free

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Same technique Information Disclosure

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CVE-2019-2725 CRITICAL POC
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Vendor StatusVendor

SUSE

Severity: Moderate
Product Status
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 Affected
SUSE Linux Enterprise High Availability Extension 16.0 Affected

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CVE-2026-53384 vulnerability details – vuln.today
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