Linux Kernel up to 7.3-rc1 kprobes __within_kprobe_blacklist use after free

CVSS Meta Temp Score
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CTI Interest Score
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7.8$0-$5k0.44

Summaryinfo

A vulnerability was found in Linux Kernel up to 7.3-rc1. It has been classified as very critical. Affected by this vulnerability is the function __within_kprobe_blacklist of the component kprobes. This manipulation causes use after free. This vulnerability appears as CVE-2026-89988. The attack requires local access. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 7.3-rc1 and classified as very critical. Affected by this vulnerability is the function __within_kprobe_blacklist of the component kprobes. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. 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: kprobes: Protect kprobe_blacklist with RCU __within_kprobe_blacklist() traverses kprobe_blacklist without holding kprobe_mutex. When a module is unloaded, kprobe_remove_area_blacklist() removes blacklist entries and immediately frees them with kfree(). A concurrent call to within_kprobe_blacklist() can therefore dereference freed memory. Furthermore, within_kprobe_blacklist() can be called in atomic or non-preemptible contexts where the sleeping kprobe_mutex cannot be taken. Protect kprobe_blacklist with RCU. Use guard(rcu)() and list_for_each_entry_rcu() for traversal, list_add_tail_rcu() for insertions, list_del_rcu() for deletions, and kfree_rcu() to reclaim entries safely after a grace period.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-89988 since 09/11/2026. The exploitation appears to be easy. Attacking locally is a requirement. Additional levels of successful authentication are necessary for exploitation. 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 09/16/2026).

Upgrading to version 6.1.188, 6.6.157, 6.12.110, 6.18.51, 7.2.5 or 7.3-rc2 eliminates this vulnerability. Applying the patch 8f406205003f741225f620f0e357ca0de71d45e3/630ed8734a02b992e8a97538179c2ece42c5210f/518d9b5568bb06f86e4434f7a30faa9612ea91ad/5da247e4d1e8661d4d6f997101d59967e8994e32/6e62cf983a2bd547e6bbd3f935539233e5f97f8f/0c4256196b3a105307e2235fbfd85e768bbcdd0f 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: 8.2
VulDB Meta Temp Score: 7.8

VulDB Base Score: 8.2
VulDB Temp Score: 7.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

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 6.1.188/6.6.157/6.12.110/6.18.51/7.2.5/7.3-rc2
Patch: 8f406205003f741225f620f0e357ca0de71d45e3/630ed8734a02b992e8a97538179c2ece42c5210f/518d9b5568bb06f86e4434f7a30faa9612ea91ad/5da247e4d1e8661d4d6f997101d59967e8994e32/6e62cf983a2bd547e6bbd3f935539233e5f97f8f/0c4256196b3a105307e2235fbfd85e768bbcdd0f

Timelineinfo

09/11/2026 CVE reserved
09/16/2026 +5 days Advisory disclosed
09/16/2026 +0 days VulDB entry created
09/16/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-89988 (🔒)
GCVE (CVE): GCVE-0-2026-89988
GCVE (VulDB): GCVE-100-405823

Entryinfo

Created: 09/16/2026 15:11
Changes: 09/16/2026 15:11 (59)
Complete: 🔍
Cache ID: 216::103

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