NULL pointer dereference in Linux serial core port unregistration
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
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- Confidentiality · integrity · availability
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- Fix status
- Partial Red Hat: 4 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
The Linux kernel from 6.5 is affected in its serial core driver. serial_core_unregister_port() dereferences port->port_dev without checking it, and that pointer is NULL when no port device is installed. Unregistering such a port causes a kernel NULL pointer dereference, as the crash trace shows through the unbind path.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
In the Linux kernel, the following vulnerability has been resolved: serial: core: fix NULL pointer dereference in serial_core_unregister_port() port->port_dev is NULL when no port device is installed: it is cleared on teardown, and never set if registration failed before serial_core_port_device_add(). serial_core_unregister_port() passes it straight to serial_core_get_ctrl_dev(), which dereferences it: KASAN: null-ptr-deref in range [0x0000000000000040-0x0000000000000047] RIP: serial_core_unregister_port Call Trace: serial8250_unregister_port serial8250_remove unbind_store Return early when there is no port device, and read port->port_dev under port_mutex. Also clear port->port_dev on the serial_core_register_port() error path, where the port device has already been removed.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Update the Linux kernel to 7.2.10 or 7.3. Red Hat's plan is none available for Red Hat Enterprise Linux 9 and 10 and Red Hat OpenShift Container Platform 4 and 5.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA Linux (Linux) Fixed in 7.2.10, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet: Fix deferred |
Not affected: 5 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
Timeline
- 2026-10-18 Threatist record created from CVE-2026-98747
- 2026-10-18 Alias added: GHSA-6854-f26p-xx8r
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-23 Affected versions changed · Red Hat
- 2026-10-23 CVSS score added · Red Hat
- 2026-11-06 Affected versions changed · Red Hat
References
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Sources
- CVE-2026-98747 · CVE Program
- CVE-2026-98747 · NVD
- FIRST EPSS
- GHSA-6854-f26p-xx8r · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98747 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences