Linux Kernel up to 6.18.38/7.1.3 libfs fs/exec.c init_pseudo assertion

CVSS Meta Temp Score
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CTI Interest Score
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5.5$0-$5k1.20

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.18.38/7.1.3. It has been declared as critical. This affects the function init_pseudo of the file fs/exec.c of the component libfs. Such manipulation leads to assertion. This vulnerability is traded as CVE-2026-64596. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.18.38/7.1.3. It has been rated as critical. Affected by this issue is the function init_pseudo of the file fs/exec.c of the component libfs. The manipulation with an unknown input leads to a assertion vulnerability. Using CWE to declare the problem leads to CWE-617. The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary. Impacted is availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: libfs: set SB_I_NOEXEC and SB_I_NODEV by default in init_pseudo() Since commit 1e7ab6f67824 ("anon_inode: rework assertions"), path_noexec() warns when an anonymous-inode file is mmap'd from a superblock that has not set SB_I_NOEXEC. dma-buf backs its files this way and never set the flag, so mmap of any exported buffer trips the warning on a CONFIG_DEBUG_VFS=y kernel: WARNING: CPU: 11 PID: 121813 at fs/exec.c:118 path_noexec+0x47/0x50 do_mmap+0x2b5/0x680 vm_mmap_pgoff+0x129/0x210 ksys_mmap_pgoff+0x177/0x240 __x64_sys_mmap+0x33/0x70 init_pseudo() sets up internal SB_NOUSER mounts that are never path-reachable. Set both flags here so every pseudo filesystem gets them by default instead of each caller setting them. SB_I_NODEV is inert for unreachable mounts. SB_I_NOEXEC has one visible effect: an executable mapping of a pseudo-fs fd, such as a dma-buf, now fails with -EPERM, which is the invariant the assertion enforces. No in-tree caller maps these executable. Reproduce on CONFIG_DEBUG_VFS=y: make -C tools/testing/selftests/dmabuf-heaps sudo ./tools/testing/selftests/dmabuf-heaps/dmabuf-heap -t system

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2026-64596 since 07/19/2026. The exploitation is known to be easy. The attack may be launched remotely. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 08/06/2026).

Upgrading to version 6.18.39, 7.1.4 or 7.2-rc1 eliminates this vulnerability. Applying the patch b9d45d328fcda4f0d3d281b7d6f12d3f181d9381/8e931557b317f0fb414839fa51fae1d5feb0ad97/6de2aeffabaafaeda819e60ec8d04f199711e11a is able to eliminate this problem.

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Productinfo

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Version

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.7
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.7
VulDB Temp Score: 5.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Assertion
CWE: CWE-617
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.18.39/7.1.4/7.2-rc1
Patch: b9d45d328fcda4f0d3d281b7d6f12d3f181d9381/8e931557b317f0fb414839fa51fae1d5feb0ad97/6de2aeffabaafaeda819e60ec8d04f199711e11a

Timelineinfo

07/19/2026 CVE reserved
08/06/2026 +18 days Advisory disclosed
08/06/2026 +0 days VulDB entry created
08/06/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-64596 (🔒)
GCVE (CVE): GCVE-0-2026-64596
GCVE (VulDB): GCVE-100-386504

Entryinfo

Created: 08/06/2026 09:52
Changes: 08/06/2026 09:52 (60)
Complete: 🔍
Cache ID: 216::103

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