CVE-2026-31706
published 2026-05-01CVE-2026-31706: In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate num_aces and harden ACE walk in smb_inherit_dacl() smb_inherit_dacl()…
PriorityP351high8.8CVSS 3.1
AVNACLPRLUINSUCHIHAH
EPSS
0.37%
29.5th percentile
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: validate num_aces and harden ACE walk in smb_inherit_dacl()
smb_inherit_dacl() trusts the on-disk num_aces value from the parent
directory's DACL xattr and uses it to size a heap allocation:
aces_base = kmalloc(sizeof(struct smb_ace) * num_aces * 2, ...);
num_aces is a u16 read from le16_to_cpu(parent_pdacl->num_aces)
without checking that it is consistent with the declared pdacl_size.
An authenticated client whose parent directory's security.NTACL is
tampered (e.g. via offline xattr corruption or a concurrent path that
bypasses parse_dacl()) can present num_aces = 65535 with minimal
actual ACE data. This causes a ~8 MB allocation (not kzalloc, so
uninitialized) that the subsequent loop only partially populates, and
may also overflow the three-way size_t multiply on 32-bit kernels.
Additionally, the ACE walk loop uses the weaker
offsetof(struct smb_ace, access_req) minimum size check rather than
the minimum valid on-wire ACE size, and does not reject ACEs whose
declared size is below the minimum.
Reproduced on UML + KASAN + LOCKDEP against the real ksmbd code path.
A legitimate mount.cifs client creates a parent directory over SMB
(ksmbd writes a valid security.NTACL xattr), then the NTACL blob on
the backing filesystem is rewritten to set num_aces = 0xFFFF while
keeping the posix_acl_hash bytes intact so ksmbd_vfs_get_sd_xattr()'s
hash check still passes. A subsequent SMB2 CREATE of a child under
that parent drives smb2_open() into smb_inherit_dacl() (share has
"vfs objects = acl_xattr" set), which fails the page allocator:
WARNING: mm/page_alloc.c:5226 at __alloc_frozen_pages_noprof+0x46c/0x9c0
Workqueue: ksmbd-io handle_ksmbd_work
__alloc_frozen_pages_noprof+0x46c/0x9c0
___kmalloc_large_node+0x68/0x130
__kmalloc_large_node_noprof+0x24/0x70
__kmalloc_noprof+0x4c9/0x690
smb_inherit_dacl+0x394/0x2430
smb2_open+0x595d/0xabe0
handle_ksmbd_work+0x3d3/0x1140
With the patch applied the add
Affected
28 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| linux | linux | — | — |
| linux | linux | >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 063a7409b0de46d7c770b65bb0338e6fdb3b1f0a | 063a7409b0de46d7c770b65bb0338e6fdb3b1f0a |
| linux | linux | >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 3e5360b422dd741cb315654a191fa73869a37414 | 3e5360b422dd741cb315654a191fa73869a37414 |
| linux | linux | >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 59c32abaaec9cdd6164811c7e864e72f7554b82d | 59c32abaaec9cdd6164811c7e864e72f7554b82d |
| linux | linux | >= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 3e4e2ea2a781018ed5d75f969e3e5606beb66e48 | 3e4e2ea2a781018ed5d75f969e3e5606beb66e48 |
| linux | linux_kernel | >= 5.15 < 6.12.84 | 6.12.84 |
| linux | linux_kernel | >= 6.13 < 6.18.25 | 6.18.25 |
| linux | linux_kernel | >= 6.19 < 7.0.2 | 7.0.2 |
| ubuntu | linux | — | — |
| ubuntu | linux-aws | — | — |
| ubuntu | linux-fips | — | — |
| ubuntu | linux-gcp | — | — |
| ubuntu | linux-gcp-6.8 | — | — |
| ubuntu | linux-gcp-fips | — | — |
| ubuntu | linux-gke | — | — |
| ubuntu | linux-gkeop | — | — |
| ubuntu | linux-hwe-7.0 | — | — |
| ubuntu | linux-ibm | — | — |
| ubuntu | linux-lowlatency | — | — |
| ubuntu | linux-lowlatency-hwe-6.8 | — | — |
| ubuntu | linux-nvidia | — | — |
| ubuntu | linux-nvidia-6.8 | — | — |
| ubuntu | linux-nvidia-lowlatency | — | — |
| ubuntu | linux-oracle | — | — |
| ubuntu | linux-oracle-6.8 | — | — |
CVSS provenance
nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
vendor_ubuntu2.0LOW
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Ubuntu
Linux kernel (Oracle) vulnerabilities
vendor_ubuntu·2026-07-23·CVSS 2.0
CVE-2026-46073 [LOW] Linux kernel (Oracle) vulnerabilities
Title: Linux kernel (Oracle) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
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)
It was discovered that some AMD Zen 5 processors supporting RDSEED
instruction did not properly handle entropy, potentially resulting in the
consumption of insufficiently random values. A loca
Ubuntu
Linux kernel (NVIDIA) vulnerabilities
vendor_ubuntu·2026-07-23·CVSS 2.0
CVE-2026-43129 [LOW] Linux kernel (NVIDIA) vulnerabilities
Title: Linux kernel (NVIDIA) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
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)
It was discovered that some AMD Zen 5 processors supporting RDSEED
instruction did not properly handle entropy, potentially resulting in the
consumption of insufficiently random values. A loca
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2026-07-23·CVSS 2.0
CVE-2026-46073 [LOW] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
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)
It was discovered that some AMD Zen 5 processors supporting RDSEED
instruction did not properly handle entropy, potentially resulting in the
consumption of insufficiently random values. A local attacke
Ubuntu
Linux kernel (GCP FIPS) vulnerabilities
vendor_ubuntu·2026-07-21·CVSS 2.0
CVE-2026-46073 [LOW] Linux kernel (GCP FIPS) vulnerabilities
Title: Linux kernel (GCP FIPS) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
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)
It was discovered that some AMD Zen 5 processors supporting RDSEED
instruction did not properly handle entropy, potentially resulting in the
consumption of insufficiently random values. A lo
Ubuntu
Linux kernel (HWE) vulnerabilities
vendor_ubuntu·2026-07-20·CVSS 2.0
CVE-2026-46073 [LOW] Linux kernel (HWE) vulnerabilities
Title: Linux kernel (HWE) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
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)
It was discovered that the Linux kernel did not properly handle shared page
fragments during socket buffer operations, collectively known as Dirty
Frag. A logic flaw existed in the XFRM ESP-in-TC
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2026-07-20·CVSS 2.0
CVE-2026-46073 [LOW] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
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)
It was discovered that some AMD Zen 5 processors supporting RDSEED
instruction did not properly handle entropy, potentially resulting in the
consumption of insufficiently random values. A local attacke
Ubuntu
Linux kernel (NVIDIA) vulnerabilities
vendor_ubuntu·2026-07-06·CVSS 2.0
CVE-2026-46009 [LOW] Linux kernel (NVIDIA) vulnerabilities
Title: Linux kernel (NVIDIA) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
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;
- x86 architecture;
- Block layer subsystem;
- Cryptographic API;
- Rados block device (RBD) driver;
- Compressed RAM block device driver;
- Character device driver;
- TPM device driver;
- Hardware crypto device drivers;
- EDAC drivers;
- GPU drivers;
- Greybus drive
Ubuntu
Linux kernel (Raspberry Pi) vulnerabilities
vendor_ubuntu·2026-07-02·CVSS 2.0
CVE-2026-46316 [LOW] 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 AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
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;
- x86 architecture;
- Block layer subsystem;
- Cryptographic API;
- Rados block device (RBD) driver;
- Compressed RAM block device driver;
- Character device driver;
- TPM device driver;
- Hardware crypto device drivers;
- EDAC drivers;
- GPU drivers;
- Greybus
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2026-07-01·CVSS 2.0
CVE-2026-46042 [LOW] Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
It was discovered that some AMD processors did not properly clear data in
the floating point divider unit during speculative execution. A local
attacker could use this to expose sensitive information. (CVE-2025-54505)
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;
- x86 architecture;
- Block layer subsystem;
- Cryptographic API;
- Rados block device (RBD) driver;
- Compressed RAM block device driver;
- Character device driver;
- TPM device driver;
- Hardware crypto device drivers;
- EDAC drivers;
- GPU drivers;
- Greybus drivers;
- HID
Red Hat
kernel: ksmbd: validate num_aces and harden ACE walk in smb_inherit_dacl()
vendor_redhat·2026-05-01
CVE-2026-31706 CWE-1284 kernel: ksmbd: validate num_aces and harden ACE walk in smb_inherit_dacl()
kernel: ksmbd: validate num_aces and harden ACE walk in smb_inherit_dacl()
A flaw was found in ksmbd, a Linux kernel module that provides an in-kernel SMB server. An authenticated client can exploit this vulnerability by manipulating the `num_aces` value within the parent directory's security.NTACL extended attribute. This manipulation causes ksmbd to attempt an excessively large heap allocation, which can lead to a Denial of Service (DoS) by exhausting available memory 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 affected
Package: kernel-rt (Red Hat Enterprise Linux 7) - Not affected
Package: kernel (Red Hat Enterprise Linux 8) - Not affected
Pac
GHSA
GHSA-8pq6-4w7p-qw4g: In the Linux kernel, the following vulnerability has been resolved:
ksmbd: validate num_aces and harden ACE walk in smb_inherit_dacl()
smb_inherit_d
ghsa_unreviewed·2026-05-01
CVE-2026-31706 [HIGH] GHSA-8pq6-4w7p-qw4g: In the Linux kernel, the following vulnerability has been resolved:
ksmbd: validate num_aces and harden ACE walk in smb_inherit_dacl()
smb_inherit_d
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: validate num_aces and harden ACE walk in smb_inherit_dacl()
smb_inherit_dacl() trusts the on-disk num_aces value from the parent
directory's DACL xattr and uses it to size a heap allocation:
aces_base = kmalloc(sizeof(struct smb_ace) * num_aces * 2, ...);
num_aces is a u16 read from le16_to_cpu(parent_pdacl->num_aces)
without checking that it is consistent with the declared pdacl_size.
An authenticated client whose parent directory's security.NTACL is
tampered (e.g. via offline xattr corruption or a concurrent path that
bypasses parse_dacl()) can present num_aces = 65535 with minimal
actual ACE data. This causes a ~8 MB allocation (not kzalloc, so
uninitialized) that the subsequent loop only partially populates,
No detection rules found.
No public exploits indexed.
Rapid7
Patch Tuesday - May 2026
blogs_rapid7·2026-05-13·CVSS 10.0
CVE-2026-41089 [CRITICAL] Patch Tuesday - May 2026
Microsoft is publishing 137 vulnerabilities on May 2026 Patch Tuesday . Microsoft is not aware of exploitation in the wild or public disclosure for any of these vulnerabilities. So far this month, Microsoft has provided patches to address 133 browser vulnerabilities, which are not included in the Patch Tuesday count above.
## Windows Netlogon: critical RCE
Anyone responsible for securing a domain controller should prioritize remediation of CVE-2026-41089 , which is a critical stack-based buffer overflow in Windows Netlogon with a CVSS v3 base score of 9.8. Exploitation leads to execution in the context of the Netlogon service, so that’s SYSTEM privileges on the domain controller. For most pentesters, that’s the point at which the customer report more or less writes itself. No privileges
Bugzilla
CVE-2026-31706 kernel: ksmbd: validate num_aces and harden ACE walk in smb_inherit_dacl()
bugzilla·2026-05-01
CVE-2026-31706 CVE-2026-31706 kernel: ksmbd: validate num_aces and harden ACE walk in smb_inherit_dacl()
CVE-2026-31706 kernel: ksmbd: validate num_aces and harden ACE walk in smb_inherit_dacl()
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: validate num_aces and harden ACE walk in smb_inherit_dacl()
smb_inherit_dacl() trusts the on-disk num_aces value from the parent
directory's DACL xattr and uses it to size a heap allocation:
aces_base = kmalloc(sizeof(struct smb_ace) * num_aces * 2, ...);
num_aces is a u16 read from le16_to_cpu(parent_pdacl->num_aces)
without checking that it is consistent with the declared pdacl_size.
An authenticated client whose parent directory's security.NTACL is
tampered (e.g. via offline xattr corruption or a concurrent path that
bypasses parse_dacl()) can present num_aces = 65535 with minimal
actual ACE data. This causes a ~8 MB al
2026-05-01
Published