CVE-2026-53385
Vulnerability Summary
Timeline
Description
In the Linux kernel, the following vulnerability has been resolved: vc_screen: fix null-ptr-deref in vcs_notifier() during concurrent vcs_write A KASAN null-ptr-deref was observed in vcs_notifier(): BUG: KASAN: null-ptr-deref in vcs_notifier+0x98/0x130 Read of size 2 at addr qmp_cmd_name: qmp_capabilities, arguments: {} The issue is a race condition in vcs_write(). When the console_lock is temporarily dropped (to copy data from userspace), the vc_data pointer obtained from vcs_vc() may become stale. After re-acquiring the lock, vcs_vc() is called again to re-validate the pointer. If the vc has been deallocated in the meantime, vcs_vc() returns NULL, and the while loop breaks (with written > 0). However, after the loop, vcs_scr_updated(vc) is still called with the now-NULL vc pointer, leading to a null pointer dereference in the notifier chain (vcs_notifier dereferences param->vc). Fix this by adding a NULL check for vc before calling vcs_scr_updated().
CVSS Metrics
- v3.1•MEDIUM•Score: 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS Trends
Current EPSS score: 0.13%• Percentile: 3%
Techniques & Countermeasures
- CWE-476•NULL Pointer Dereference
The product dereferences a pointer that it expects to be valid but is NULL.
Affected Systems
- debian•linux
< 5.10.262-1 | < 6.1.177-1 | < 6.12.95-1 | < 7.0.14-1
- debian•linux-6.1
< 6.1.177-1~deb11u1
- ubuntu•linux
all | all | all | all | < 7.0.0-31.31
- ubuntu•linux-allwinner-5.19
all
- ubuntu•linux-aws
all | all | all | all | < 7.0.0-1012.12
- ubuntu•linux-aws-5.0
all
- ubuntu•linux-aws-5.11
all
- ubuntu•linux-aws-5.13
all
- ubuntu•linux-aws-5.15
all
- ubuntu•linux-aws-5.19
all
- ubuntu•linux-aws-5.3
all
- ubuntu•linux-aws-5.4
all
- ubuntu•linux-aws-5.8
all
- ubuntu•linux-aws-6.14
all
- ubuntu•linux-aws-6.17
all
- ubuntu•linux-aws-6.2
all
- ubuntu•linux-aws-6.5
all
- ubuntu•linux-aws-6.8
all
- ubuntu•linux-aws-7.0
all | < 7.0.0-1012.12~24.04.1
- ubuntu•linux-aws-fips
all
- ubuntu•linux-azure
all | all | all | all | all
- ubuntu•linux-azure-5.11
all
- ubuntu•linux-azure-5.13
all
- ubuntu•linux-azure-5.15
all
- ubuntu•linux-azure-5.19
all
- ubuntu•linux-azure-5.3
all
- ubuntu•linux-azure-5.4
all
- ubuntu•linux-azure-5.8
all
- ubuntu•linux-azure-6.11
all
- ubuntu•linux-azure-6.14
all
- ubuntu•linux-azure-6.17
all
- ubuntu•linux-azure-6.2
all
- ubuntu•linux-azure-6.5
all
- ubuntu•linux-azure-6.8
all
- ubuntu•linux-azure-7.0
all
- ubuntu•linux-azure-edge
all
- ubuntu•linux-azure-fde
all | all | all | all
- ubuntu•linux-azure-fde-5.15
all
- ubuntu•linux-azure-fde-5.19
all
- ubuntu•linux-azure-fde-6.14
all
- ubuntu•linux-azure-fde-6.17
all
- ubuntu•linux-azure-fde-6.2
all
- ubuntu•linux-azure-fde-6.8
all
- ubuntu•linux-azure-fde-7.0
all
- ubuntu•linux-azure-fips
all
- ubuntu•linux-azure-nvidia
all
- ubuntu•linux-azure-nvidia-6.14
all
- ubuntu•linux-bluefield
all | all
- ubuntu•linux-fips
all
- ubuntu•linux-gcp
all | all | all | all | all | < 7.0.0-1011.11
Showing first 50 affected entries in server-rendered view.
References (18)
- https://git.kernel.org/stable/c/43a6281790273c1b0a9ab76609ff0245b968f1e6
- https://git.kernel.org/stable/c/b6bbb85cf45bf0b070e741997fe0af3a772c5ad5
- https://git.kernel.org/stable/c/ff4806202749a51938236214adc0281481a57366
- https://git.kernel.org/stable/c/8232fca738011ca2ec865b46ec721d1796dc0580
- https://git.kernel.org/stable/c/73049768ad57145acd337102c5aa3c788e6642c8
- https://git.kernel.org/stable/c/7cc3dd79777f6ae4625ec37e84dd18a26dc88bde
- https://git.kernel.org/stable/c/74be188eb2dc1c99d63986167b9a67d415fe7326
- https://git.kernel.org/stable/c/09a43e81279b8da15526da09877134b8bcf618b0
- https://git.kernel.org/stable/c/a287620312dc6dcb9a093417a0e589bf30fcf38a
- https://ubuntu.com/security/CVE-2026-53385
- https://www.cve.org/CVERecord?id=CVE-2026-53385
- https://git.kernel.org/linus/a287620312dc6dcb9a093417a0e589bf30fcf38a
- https://security-tracker.debian.org/tracker/CVE-2026-53385
- https://ubuntu.com/security/notices/USN-8726-1
- https://ubuntu.com/security/notices/USN-8727-1
- https://ubuntu.com/security/notices/USN-8728-1
- https://ubuntu.com/security/notices/USN-8760-1
- https://ubuntu.com/security/notices/USN-8726-2