VulnerabilityPublished 19 Jul 2026Updated 20 Jul 2026

CVE-2026-53384: Linux kernel · serial: 8250_dw: unregister 8250 port if clk_notifier_register() fails

Source GCVE Database

Authoritative record:CVE-2026-53384· Critical 9.8

Not known to be exploited · CVSS 9.8 Critical · fixed in d72650a4f334581b23a1892b888a4cb1be142f76 : patch Linux kernel as a priority.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score

9.8Critical

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.5% chance of exploitation in 30 days – higher than 43% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in d72650a4f334581b23a1892b888a4cb1be142f76, ccdf4510a3873b14e5e348cdb038717996f09fda, 778b9dda4b24005a27bcd9c35c110bf8d7f259ca +4

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 19 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-8qr8-6qvc-c8x9

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 57f83e5dd6a33c4696699954784f8fee789b1d0c, < d72650a4f334581b23a1892b888a4cb1be142f76	Fixed in d72650a4f334581b23a1892b888a4cb1be142f76
LinuxLinux	Affected ≥ 57f83e5dd6a33c4696699954784f8fee789b1d0c, < ccdf4510a3873b14e5e348cdb038717996f09fda	Fixed in ccdf4510a3873b14e5e348cdb038717996f09fda
LinuxLinux	Affected ≥ 57f83e5dd6a33c4696699954784f8fee789b1d0c, < 778b9dda4b24005a27bcd9c35c110bf8d7f259ca	Fixed in 778b9dda4b24005a27bcd9c35c110bf8d7f259ca
LinuxLinux	Affected ≥ 57f83e5dd6a33c4696699954784f8fee789b1d0c, < 511d2b92f8d20de04acafab676150d26fb5c67f4	Fixed in 511d2b92f8d20de04acafab676150d26fb5c67f4
LinuxLinux	Affected ≥ 57f83e5dd6a33c4696699954784f8fee789b1d0c, < 10fc708b4de7f86002d2d735a2dbf3b5b7f65692	Fixed in 10fc708b4de7f86002d2d735a2dbf3b5b7f65692
LinuxLinux	Affected ≥ 57f83e5dd6a33c4696699954784f8fee789b1d0c, < 07ffe414a708ae60551401cec5d727ed156b8caf	Fixed in 07ffe414a708ae60551401cec5d727ed156b8caf

AI-suggested

The vulnerability description indicates the issue has been resolved in the Linux kernel source by unregistering the port on clk_notifier_register() failure. Users should monitor official Linux kernel advisories and apply updates when available.

Description

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.

Impact

The vulnerability can lead to use-after-free conditions where the kernel accesses freed memory via the stale 8250 port slot. This may cause system instability or crashes. There is no evidence of known exploits in the wild. The impact is limited to affected Linux kernel serial driver instances where the failure scenario occurs.

Summary

In the Linux kernel serial driver 8250_dw, the dw8250_probe() function registers an 8250 port and then attempts to register a clock notifier if the device has a clock. If clk_notifier_register() fails, the probe function returns an error but does not unregister the previously registered 8250 port. The corresponding unregister function is only called during device removal, which does not occur on probe failure. As a result, the port slot remains occupied and references freed driver data, creating a use-after-free vulnerability. The fix involves unregistering the port if clk_notifier_register() fails to prevent stale references.

References

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