CVE-2026-64391
published 2026-07-25CVE-2026-64391: In the Linux kernel, the following vulnerability has been resolved: ksmbd: use opener credentials for ADS I/O Alternate data streams are stored as xattrs…
PriorityP349critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
0.46%
37.9th percentile
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: use opener credentials for ADS I/O
Alternate data streams are stored as xattrs. Unlike regular file I/O,
their read and write paths therefore call VFS xattr helpers which recheck
inode permissions and LSM policy using the current task credentials.
Run ADS I/O with the credentials captured when the SMB handle was opened.
Affected
26 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| linux | linux | — | — |
| linux | linux | >= f44158485826c076335d6860d35872271a83791d < a8f5d39971bbad9340d49cd41b0e2da9452a649d | a8f5d39971bbad9340d49cd41b0e2da9452a649d |
| linux | linux | >= f44158485826c076335d6860d35872271a83791d < 2b4592cea214683de0f2ce6f8c22c097fb0ea1ab | 2b4592cea214683de0f2ce6f8c22c097fb0ea1ab |
| linux | linux | >= f44158485826c076335d6860d35872271a83791d < 52a56cf53ec834c44ac1b4d16d585f26613ee5ce | 52a56cf53ec834c44ac1b4d16d585f26613ee5ce |
| linux | linux | >= f44158485826c076335d6860d35872271a83791d < baa5e094886fffa7e6272edcb5e08be5ce28262c | baa5e094886fffa7e6272edcb5e08be5ce28262c |
| linux | linux_kernel | >= 5.15 < 6.12.96 | 6.12.96 |
| linux | linux_kernel | >= 6.13 < 6.18.39 | 6.18.39 |
| linux | linux_kernel | >= 6.19 < 7.1.4 | 7.1.4 |
| ubuntu | linux | — | — |
| ubuntu | linux-aws | — | — |
| ubuntu | linux-aws-7.0 | — | — |
| ubuntu | linux-azure | — | — |
| ubuntu | linux-azure-7.0 | — | — |
| ubuntu | linux-gcp | — | — |
| ubuntu | linux-gcp-7.0 | — | — |
| ubuntu | linux-gke | — | — |
| ubuntu | linux-hwe-7.0 | — | — |
| ubuntu | linux-ibm | — | — |
| ubuntu | linux-nvidia-7.0 | — | — |
| ubuntu | linux-nvidia-bos | — | — |
| ubuntu | linux-nvidia-tegra | — | — |
| ubuntu | linux-oem-7.0 | — | — |
| ubuntu | linux-oracle | — | — |
| ubuntu | linux-oracle-7.0 | — | — |
| ubuntu | linux-raspi | — | — |
CVSS provenance
nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
vendor_redhat9.8CRITICAL
vendor_ubuntu9.1CRITICAL
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
VulDB
Linux Kernel up to 6.12.95/6.18.38/7.1.3 ksmbd permission (Nessus ID 329913)
vuldb·2026-07-27
CVE-2026-64391 Linux Kernel up to 6.12.95/6.18.38/7.1.3 ksmbd permission (Nessus ID 329913)
A vulnerability described as very critical has been identified in Linux Kernel up to 6.12.95/6.18.38/7.1.3. Affected is an unknown function of the component ksmbd. Executing a manipulation can lead to permission issues.
This vulnerability is handled as CVE-2026-64391. The attack can be executed remotely. There is not any exploit available.
Upgrading the affected component is recommended.
GHSA
In the Linux kernel, the following vulnerability has been resolved: ksmbd: use opener credentials for ADS I/O Alternate data streams are stored as xattrs.
ghsa_unreviewed·2026-07-25
CVE-2026-64391 In the Linux kernel, the following vulnerability has been resolved: ksmbd: use opener credentials for ADS I/O Alternate data streams are stored as xattrs.
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: use opener credentials for ADS I/O
Alternate data streams are stored as xattrs. Unlike regular file I/O,
their read and write paths therefore call VFS xattr helpers which recheck
inode permissions and LSM policy using the current task credentials.
Run ADS I/O with the credentials captured when the SMB handle was opened.
Ubuntu
Linux kernel (Oracle) vulnerabilities
vendor_ubuntu·2026-09-29·CVSS 9.1
CVE-2026-64191 [CRITICAL] Linux kernel (Oracle) vulnerabilities
Title: Linux kernel (Oracle) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)
Several security issues were d
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2026-09-22·CVSS 9.1
CVE-2026-63869 [CRITICAL] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- ARM64 architecture;
- User-space API (UAPI);
- Kernel build system;
- ARM32 architecture;
- RISC-V architecture;
- S390 architecture;
Ubuntu
Linux kernel (Azure) vulnerabilities
vendor_ubuntu·2026-09-22·CVSS 9.1
CVE-2026-52938 [CRITICAL] Linux kernel (Azure) vulnerabilities
Title: Linux kernel (Azure) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)
Several security issues were di
Ubuntu
Linux kernel (NVIDIA BaseOS) vulnerabilities
vendor_ubuntu·2026-09-22
CVE-2026-64504 Linux kernel (NVIDIA BaseOS) vulnerabilities
Title: Linux kernel (NVIDIA BaseOS) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- User-space API (UAPI);
- Kernel build system;
- ARM32 architecture;
- ARM64 architecture;
- RISC-V architecture;
- S390 architecture;
- x86 architecture;
- Block layer subsystem;
- Cryptographic API;
- Compute Acceleration Framework;
- Intel NPU Driver;
- ACPI drivers;
- Android drivers;
- Drivers core;
- Compressed RAM block device driver;
- Bluetooth drivers;
- Character device driver;
- Hardware random number generator core;
- CPU frequency scaling framework;
- Hardware crypto device drivers
Ubuntu
Linux kernel (IBM) vulnerabilities
vendor_ubuntu·2026-09-21·CVSS 9.1
CVE-2026-63869 [CRITICAL] Linux kernel (IBM) vulnerabilities
Title: Linux kernel (IBM) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- ARM64 architecture;
- User-space API (UAPI);
- Kernel build system;
- ARM32 architecture;
- RISC-V architecture;
- S390 architec
Ubuntu
Linux kernel (NVIDIA Tegra) vulnerabilities
vendor_ubuntu·2026-09-18·CVSS 9.1
CVE-2026-53358 [CRITICAL] Linux kernel (NVIDIA Tegra) vulnerabilities
Title: Linux kernel (NVIDIA Tegra) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- ARM64 architecture;
- User-space API (UAPI);
- Kernel build system;
- ARM32 architecture;
- PowerPC architecture;
- RIS
Ubuntu
Linux kernel (Raspberry Pi) vulnerabilities
vendor_ubuntu·2026-09-18·CVSS 9.1
CVE-2026-64504 [CRITICAL] Linux kernel (Raspberry Pi) vulnerabilities
Title: Linux kernel (Raspberry Pi) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- ARM64 architecture;
- User-space API (UAPI);
- Kernel build system;
- ARM32 architecture;
- RISC-V architecture;
- S390
Ubuntu
Linux kernel (NVIDIA) vulnerabilities
vendor_ubuntu·2026-09-15
CVE-2026-63869 Linux kernel (NVIDIA) vulnerabilities
Title: Linux kernel (NVIDIA) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- User-space API (UAPI);
- Kernel build system;
- ARM32 architecture;
- ARM64 architecture;
- RISC-V architecture;
- S390 architecture;
- x86 architecture;
- Block layer subsystem;
- Cryptographic API;
- Compute Acceleration Framework;
- Intel NPU Driver;
- ACPI drivers;
- Android drivers;
- Drivers core;
- Compressed RAM block device driver;
- Bluetooth drivers;
- Character device driver;
- Hardware random number generator core;
- CPU frequency scaling framework;
- Hardware crypto device drivers;
- Buf
Ubuntu
Linux kernel (GCP) vulnerabilities
vendor_ubuntu·2026-09-07·CVSS 9.1
CVE-2026-52938 [CRITICAL] Linux kernel (GCP) vulnerabilities
Title: Linux kernel (GCP) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
It was discovered that some AMD Zen 2 processors did not properly isolate
shared resources in the operation cache. A local attacker could possibly
use this issue to corrupt instructions executed at a higher privilege
level, resulting in privilege escalation. (CVE-2025-54518)
Several security issues were disc
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2026-09-07·CVSS 9.1
CVE-2026-64504 [CRITICAL] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- ARM64 architecture;
- User-space API (UAPI);
- Kernel build system;
- ARM32 architecture;
- RISC-V architecture;
- S390 architecture;
Ubuntu
Linux kernel (OEM) vulnerabilities
vendor_ubuntu·2026-09-07·CVSS 9.1
CVE-2026-63869 [CRITICAL] Linux kernel (OEM) vulnerabilities
Title: Linux kernel (OEM) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some Arm processors could complete a broadcast
translation lookaside buffer (TLB) invalidation before memory writes made
through the invalidated translation were globally observed. A local
attacker could possibly use this to write to memory after permission to do
so had been revoked, bypassing memory protections or escalating privileges.
(CVE-2025-10263)
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- ARM64 architecture;
- User-space API (UAPI);
- Kernel build system;
- ARM32 architecture;
- RISC-V architecture;
- S390 architec
Red Hat
kernel: ksmbd: use opener credentials for ADS I/O
vendor_redhat·2026-07-25·CVSS 9.8
CVE-2026-64391 [CRITICAL] CWE-250 kernel: ksmbd: use opener credentials for ADS I/O
kernel: ksmbd: use opener credentials for ADS I/O
A flaw was found in ksmbd, the in-kernel Server Message Block (SMB) daemon. This vulnerability allows a remote attacker to bypass security restrictions by incorrectly handling credentials for Alternate Data Streams (ADS) input/output (I/O) operations. Instead of using the credentials established when the SMB handle was opened, ksmbd uses the current task's credentials. This misconfiguration can lead to a bypass of inode permissions and Linux Security Module (LSM) policies, potentially resulting in privilege escalation and unauthorized access to system resources.
Package: kernel (Red Hat Enterprise Linux 10) - Not affected
Package: kernel (Red Hat Enterprise Linux 6) - Not affected
Package: kernel (Red Hat Enterprise Linux 7) - Not affec
No detection rules found.
No public exploits indexed.
2026-07-25
Published