Linux Kernel up to 7.0.2 privcmd munmap double free

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7.6	$0-$5k	0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 7.0.2. It has been classified as critical. Affected by this issue is the function munmap of the component privcmd. This manipulation causes double free. This vulnerability is registered as CVE-2026-31787. No exploit is available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 7.0.2. It has been declared as critical. Affected by this vulnerability is the function munmap of the component privcmd. The manipulation with an unknown input leads to a double free vulnerability. The CWE definition for the vulnerability is CWE-415. The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: xen/privcmd: fix double free via VMA splitting privcmd_vm_ops defines .close (privcmd_close), but neither .may_split nor .open. When userspace does a partial munmap() on a privcmd mapping, the kernel splits the VMA via __split_vma(). Since may_split is NULL, the split is allowed. vm_area_dup() copies vm_private_data (a pages array allocated in alloc_empty_pages()) into the new VMA without any fixup, because there is no .open callback. Both VMAs now point to the same pages array. When the unmapped portion is closed, privcmd_close() calls: - xen_unmap_domain_gfn_range() - xen_free_unpopulated_pages() - kvfree(pages) The surviving VMA still holds the dangling pointer. When it is later destroyed, the same sequence runs again, which leads to a double free. Fix this issue by adding a .may_split callback denying the VMA split. This is XSA-487 / CVE-2026-31787

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-31787 since 03/09/2026. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 05/30/2026).

The vulnerability scanner Nessus provides a plugin with the ID 317729 (SUSE SLES12 Security Update : kernel (SUSE-SU-2026:2068-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.10.254, 5.15.204, 6.1.170, 6.6.137, 6.12.85, 6.18.26 or 7.0.3 eliminates this vulnerability. Applying the patch dbf862ce9f009128ab86b234d91413a3e450beb4/2b985d3a024b9e8c24e21671b34e855569763808/1576ff3869cbd3620717195f971c85b7d7fd62b5/402d84ad9e89bd4cbfd07ca8598532b7021daf95/2894a351fe2ea8684919d36df3188b9a35e3926f/446ee446d9ae66f36e95c3c90bbcc4e56b94cde0/71bf829800758a6e3889096e4754ef47ba7fc850 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (317729) and EUVD (EUVD-2026-26365). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.10.253
• 5.15.203
• 6.1.169
• 6.6.136
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
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• 6.12.73
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• 6.12.75
• 6.12.76
• 6.12.77
• 6.12.78
• 6.12.79
• 6.12.80
• 6.12.81
• 6.12.82
• 6.12.83
• 6.12.84
• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
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• 6.18.17
• 6.18.18
• 6.18.19
• 6.18.20
• 6.18.21
• 6.18.22
• 6.18.23
• 6.18.24
• 6.18.25
• 7.0.0
• 7.0.1
• 7.0.2

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.6

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

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

Exploitinginfo

Class: Double free
CWE: CWE-415 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 317729
Nessus Name: SUSE SLES12 Security Update : kernel (SUSE-SU-2026:2068-1)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.254/5.15.204/6.1.170/6.6.137/6.12.85/6.18.26/7.0.3
Patch: dbf862ce9f009128ab86b234d91413a3e450beb4/2b985d3a024b9e8c24e21671b34e855569763808/1576ff3869cbd3620717195f971c85b7d7fd62b5/402d84ad9e89bd4cbfd07ca8598532b7021daf95/2894a351fe2ea8684919d36df3188b9a35e3926f/446ee446d9ae66f36e95c3c90bbcc4e56b94cde0/71bf829800758a6e3889096e4754ef47ba7fc850

Timelineinfo

03/09/2026 CVE reserved
04/30/2026 +51 days Advisory disclosed
04/30/2026 +0 days VulDB entry created
05/30/2026 +30 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-31787 (🔒)
GCVE (CVE): GCVE-0-2026-31787
GCVE (VulDB): GCVE-100-360295
EUVD: 🔒

Entryinfo

Created: 04/30/2026 13:32
Updated: 05/30/2026 14:41
Changes: 04/30/2026 13:32 (59), 04/30/2026 15:25 (1), 05/30/2026 14:41 (2)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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