Linux Kernel up to 7.2-rc2 mcast igmp6_event_query use after free

CVSS Meta Temp Score
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CTI Interest Score
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9.5$5k-$25k0.00+

Summaryinfo

A vulnerability was found in Linux Kernel up to 7.2-rc2. It has been rated as very critical. Affected by this vulnerability is the function igmp6_event_query of the component mcast. The manipulation leads to use after free. This vulnerability is traded as CVE-2026-72322. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in Linux Kernel up to 7.2-rc2 and classified as very critical. This issue affects the function igmp6_event_query of the component mcast. The manipulation with an unknown input leads to a use after free vulnerability. Using CWE to declare the problem leads to CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: ipv6: mcast: Fix potential UAF in MLD delayed work A race condition exists between device teardown and incoming MLD query processing, leading to a Use-After-Free in the MLD delayed work. During device destruction, the primary reference to inet6_dev is dropped, which can drop its refcount to 0. The actual freeing of inet6_dev memory is deferred via RCU. Concurrently, the packet receive path runs under RCU read lock and obtains the inet6_dev pointer. Because the memory is RCU-protected, CPU-0 can safely dereference inet6_dev even if its refcount has hit 0. However, if CPU-0 calls igmp6_event_query() and schedules delayed work, it attempts to acquire a reference using in6_dev_hold(). This increments the refcount from 0 to 1, triggering a "refcount_t: addition on 0" warning. Since the inet6_dev memory is still scheduled to be freed after the RCU grace period, the device is freed while the work is still scheduled. When the work runs, it accesses the freed memory, causing a kernel panic. Fix this by using refcount_inc_not_zero() (via a new helper in6_dev_hold_safe()) to prevent acquiring a reference if the device is already being destroyed. If the refcount is 0, we do not schedule the work.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2026-72322 since 08/09/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details are known, but no exploit is available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 08/15/2026).

Upgrading to version 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.5 or 7.2-rc3 eliminates this vulnerability. Applying the patch f12b63ef26a035c5a29b3ef56401e38199010d4a/0401d6cf7877c9be36652385dfcbf7f891b8b590/f03b0a45535d49bdab7e502efaacee205b2a7865/9815e834f5ff8b39e0ea9f0dbd532f4a3b8f0785/ebbebf6cee950d7f1c81990256c0eae9e62572ae/9ce741c22df4fd9546e30306317ac7df3607e48f/0458ba1cda830ba4ccfcd9e19c0891438bcdbe4e/9b26518b6896a16b809b1e42986f4ebac7bccc1e is able to eliminate this problem.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 10.0
VulDB Meta Temp Score: 9.5

VulDB Base Score: 10.0
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: Use after free
CWE: CWE-416 / CWE-119
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 5.10.261/5.15.212/6.1.178/6.6.145/6.12.97/6.18.40/7.1.5/7.2-rc3
Patch: f12b63ef26a035c5a29b3ef56401e38199010d4a/0401d6cf7877c9be36652385dfcbf7f891b8b590/f03b0a45535d49bdab7e502efaacee205b2a7865/9815e834f5ff8b39e0ea9f0dbd532f4a3b8f0785/ebbebf6cee950d7f1c81990256c0eae9e62572ae/9ce741c22df4fd9546e30306317ac7df3607e48f/0458ba1cda830ba4ccfcd9e19c0891438bcdbe4e/9b26518b6896a16b809b1e42986f4ebac7bccc1e

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-2026-72322 (🔒)
GCVE (CVE): GCVE-0-2026-72322
GCVE (VulDB): GCVE-100-390929

Entryinfo

Created: 08/15/2026 16:22
Changes: 08/15/2026 16:22 (59)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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