Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc2 tracing create_var_ref memory leak

CVSS Meta Temp Score
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CTI Interest Score
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4.5$0-$5k0.32+

Summaryinfo

A vulnerability, which was classified as problematic, was found in Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc2. This affects the function create_var_ref of the component tracing. Executing a manipulation can lead to memory leak. The identification of this vulnerability is CVE-2026-97923. The attack may be launched remotely. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic was found in Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc2. This vulnerability affects the function create_var_ref of the component tracing. The manipulation with an unknown input leads to a memory leak vulnerability. The CWE definition for the vulnerability is CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: tracing: Free histogram the var ref when its initialization fails create_var_ref() allocates a VAR_REF hist_field and then calls init_var_ref() to fill it in. When that fails the field is leaked. commit 656fe2ba85e8 ("tracing: Use hist trigger's var_ref array to destroy var_refs") made destroy_hist_field() return early for HIST_FIELD_FL_VAR_REF, since var refs are freed by walking the trigger's var_refs[] array instead. create_var_ref() adds the field to that array only after init_var_ref() has succeeded, so on this path the field is in neither place and nothing frees it. The call was correct when it was written, before var refs were taken out of destroy_hist_field(). init_var_ref() cannot free it either. The caller owns the field, so init_var_ref() undoes only its own string allocations and leaves the field alone. Freeing it there would leave create_var_ref() passing freed memory to destroy_hist_field(), which reads its flags. Call __destroy_hist_field(), which frees the field without consulting the flag.

The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2026-97923 since 09/25/2026. The exploitation appears to be easy. The attack can be initiated remotely. Additional levels of successful authentication are needed for exploitation. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1499.

Upgrading to version 6.12.111, 6.18.53, 7.2.7 or 7.3-rc3 eliminates this vulnerability. Applying the patch 74375caa20fe5165807b4334c783d1790b01f02a/222abcbe7866fef04563b6eb89fb21f627dcbc77/a69baeac38677270656e85753d93856a076dee57/516001d53e6b2ea95a251ee2ef54a1a689a3fd58 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.7
VulDB Meta Temp Score: 4.5

VulDB Base Score: 4.7
VulDB Temp Score: 4.5
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: Memory leak
CWE: CWE-401 / CWE-404
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 6.12.111/6.18.53/7.2.7/7.3-rc3
Patch: 74375caa20fe5165807b4334c783d1790b01f02a/222abcbe7866fef04563b6eb89fb21f627dcbc77/a69baeac38677270656e85753d93856a076dee57/516001d53e6b2ea95a251ee2ef54a1a689a3fd58

Timelineinfo

09/25/2026 Advisory disclosed
09/25/2026 +0 days CVE reserved
09/25/2026 +0 days VulDB entry created
09/25/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-97923 (🔒)
GCVE (CVE): GCVE-0-2026-97923
GCVE (VulDB): GCVE-100-410104

Entryinfo

Created: 09/25/2026 14:41
Changes: 09/25/2026 14:41 (59)
Complete: 🔍
Cache ID: 216::103

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