Linux Kernel up to 6.6.147/6.12.100/6.18.39/7.1.4 Locking/RT rt_spin_unlock use after free

CVSS Meta Temp Score
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CTI Interest Score
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8.4$0-$5k0.00-

Summaryinfo

A vulnerability labeled as very critical has been found in Linux Kernel up to 6.6.147/6.12.100/6.18.39/7.1.4. The affected element is the function rt_spin_unlock of the component Locking/RT. Executing a manipulation can lead to use after free. The identification of this vulnerability is CVE-2026-72069. The attack can only be executed locally. There is no exploit available.

Detailsinfo

A vulnerability classified as very critical was found in Linux Kernel up to 6.6.147/6.12.100/6.18.39/7.1.4. This vulnerability affects the function rt_spin_unlock of the component Locking/RT. 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. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: locking/rt: Fix the incorrect RCU protection in rt_spin_unlock() rt_spin_unlock() releases the RCU protection before unlocking the lock. That opens the door for the following UAF scenario: T1 T2 spin_lock(&p->lock); rcu_read_lock(); invalidate(p); p = rcu_dereference(ptr); rcu_assign_pointer(ptr, NULL); if (!p) return; spin_unlock(&p->lock); spin_lock(&p->lock) lock(&lock->lock); rcu_read_lock(); kfree_rcu(p); rcu_read_unlock(); .... spin_unlock(&p->lock) rcu_read_unlock(); // Ends grace period rcu_do_batch() kfree(p); UAF -> rt_mutex_cmpxchg_release(&lock->lock...) Regular spinlocks keep preemption disabled accross the unlock operation, which provides full RCU protection, but the RT substitution fails to resemble that. Same applies for the rwlock substitution. Move the rcu_read_unlock() invocation past the unlock operations to match the non-RT semantics. This makes it asymmetric vs. rt_xxx_lock(), but that's harmless as the caller needs to hold RCU read lock across the lock operation. The migrate_enable() call stays before the unlock operation because there is no per CPU operation in the unlock path which would require migration to be kept disabled.

The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2026-72069 since 08/09/2026. The exploitation appears to be easy. The attack needs to be approached locally. 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 08/15/2026).

Upgrading to version 6.6.148, 6.12.101, 6.18.40, 7.1.5 or 7.2-rc1 eliminates this vulnerability. Applying the patch 3cfaac77b3c32ac3940df28866de263c3f45d24c/1f0d56d3f1e88f20f6e46109402f8c15d59bac37/633cadbc0b8323f5cc140a285d2432089dbb534e/83f9fb561c1c3917e19f95523dd933c7d30291aa/89038cc87d80c77e7aa6f42a64b2573b74af339f is able to eliminate this problem.

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Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.8
VulDB Meta Temp Score: 8.4

VulDB Base Score: 8.8
VulDB Temp Score: 8.4
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: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

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 6.6.148/6.12.101/6.18.40/7.1.5/7.2-rc1
Patch: 3cfaac77b3c32ac3940df28866de263c3f45d24c/1f0d56d3f1e88f20f6e46109402f8c15d59bac37/633cadbc0b8323f5cc140a285d2432089dbb534e/83f9fb561c1c3917e19f95523dd933c7d30291aa/89038cc87d80c77e7aa6f42a64b2573b74af339f

Timelineinfo

08/09/2026 CVE reserved
08/15/2026 +6 days Advisory disclosed
08/15/2026 +0 days VulDB entry created
08/15/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-72069 (🔒)
GCVE (CVE): GCVE-0-2026-72069
GCVE (VulDB): GCVE-100-390484

Entryinfo

Created: 08/15/2026 11:49
Changes: 08/15/2026 11:49 (59)
Complete: 🔍
Cache ID: 216::103

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