Linux Kernel up to 6.6.144/6.12.95/6.18.38/7.1.3 mm/slab slub_debug_orig_size/krealloc allocation of resources

CVSS Meta Temp Score
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CTI Interest Score
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9.5$0-$5k3.17-

Summaryinfo

A vulnerability labeled as very critical has been found in Linux Kernel up to 6.6.144/6.12.95/6.18.38/7.1.3. Affected is the function slub_debug_orig_size/krealloc of the component mm/slab. Such manipulation leads to allocation of resources. This vulnerability is uniquely identified as CVE-2026-64368. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.144/6.12.95/6.18.38/7.1.3 and classified as very critical. Affected by this issue is the function slub_debug_orig_size/krealloc of the component mm/slab. The manipulation with an unknown input leads to a allocation of resources vulnerability. Using CWE to declare the problem leads to CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. Impacted is confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: mm/slab: do not limit zeroing to orig_size when only red zoning is enabled When init (zeroing) on allocation is requested, for kmalloc() we generally have to zero the full object size even if a smaller size is requested, in order to provide krealloc()'s __GFP_ZERO guarantees. But if we track the requested size, krealloc() uses that information to do the right thing, so we can zero only the requested size. With red zoning also enabled, any extra size became part of the red zone, so it must not be zeroed and thus we must zero only the requested size. However the current check is imprecise, and will trigger also when only SLAB_RED_ZONE is enabled without SLAB_STORE_USER (which enables tracking the requested size). This means enabling red zoning alone can compromise krealloc()'s __GFP_ZERO contract. Fix this by using slub_debug_orig_size() instead, which is the exact check for whether the requested size is tracked. We don't need to care if red zoning is also enabled or not. Also update and expand the comment accordingly.

The advisory is available at git.kernel.org. This vulnerability is handled as CVE-2026-64368 since 07/19/2026. The exploitation is known to be easy. The attack may be launched remotely. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 07/25/2026). This vulnerability is assigned to T1499 by the MITRE ATT&CK project.

Upgrading to version 6.6.145, 6.12.96, 6.18.39, 7.1.4 or 7.2-rc1 eliminates this vulnerability. Applying the patch 6256899c3a34674bba6076884aedbba49fc695e4/7e706d50fa119eead6376bf0ef973e8d73a96030/2382971aaaef5bf85a651234c64906f59580b8be/0d18ccef142f04433dfb2a0c120cf223d2b8a42c/648927ceb84021a25a0fbd5673740956f318d534 is able to eliminate this problem.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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: 9.9
VulDB Meta Temp Score: 9.5

VulDB Base Score: 9.9
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Allocation of resources
CWE: CWE-770 / CWE-400 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

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 6.6.145/6.12.96/6.18.39/7.1.4/7.2-rc1
Patch: 6256899c3a34674bba6076884aedbba49fc695e4/7e706d50fa119eead6376bf0ef973e8d73a96030/2382971aaaef5bf85a651234c64906f59580b8be/0d18ccef142f04433dfb2a0c120cf223d2b8a42c/648927ceb84021a25a0fbd5673740956f318d534

Timelineinfo

07/19/2026 CVE reserved
07/25/2026 +6 days Advisory disclosed
07/25/2026 +0 days VulDB entry created
07/25/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-64368 (🔒)
GCVE (CVE): GCVE-0-2026-64368
GCVE (VulDB): GCVE-100-383162

Entryinfo

Created: 07/25/2026 17:27
Changes: 07/25/2026 17:27 (59)
Complete: 🔍
Cache ID: 216::103

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