Linux Kernel up to 7.2-rc4 mt7921 mt7921_mac_tx_free null pointer dereference

| CVSS Meta Temp Score | Current Exploit Price (≈) | CTI Interest Score |
|---|---|---|
| 7.2 | $0-$5k | 1.07+ |
Summary
A vulnerability was found in Linux Kernel up to 6.6.147/6.12.100/6.18.41/7.1.5/7.2-rc4 and classified as critical. This affects the function mt7921_mac_tx_free of the component mt7921. Executing a manipulation can lead to null pointer dereference.
This vulnerability appears as CVE-2026-68194. The attack may be performed from remote. There is no available exploit.
Details
A vulnerability was found in Linux Kernel up to 6.6.147/6.12.100/6.18.41/7.1.5/7.2-rc4. It has been declared as critical. This vulnerability affects the function mt7921_mac_tx_free of the component mt7921. The manipulation with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. As an impact it is known to affect availability. CVE summarizes:
In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7921: drop TXRX_NOTIFY on non-mmio buses PKT_TYPE_TXRX_NOTIFY is an mmio-only event, but mt7921_rx_check() and mt7921_queue_rx_skb() dispatch it to mt7921_mac_tx_free() on every bus. mt7921_mac_tx_free() cleans the DMA tx queues with mt76_queue_tx_cleanup(), which calls queue_ops->tx_cleanup(). Only the mmio queue ops implement that callback; on USB and SDIO it is NULL, so a TXRX_NOTIFY there calls a NULL pointer in the RX worker: BUG: kernel NULL pointer dereference, address: 0000000000000000 RIP: 0010:0x0 Call Trace: mt7921_mac_tx_free+0x64/0x310 [mt7921_common] mt7921_rx_check+0x5f/0xf0 [mt7921_common] mt76u_rx_worker+0x1b9/0x620 [mt76_usb] Drop the event on non-mmio buses via mt76_is_mmio(), as in commit 5683e1488aa9 ("wifi: mt76: connac: do not check WED status for non-mmio devices").
The advisory is available at git.kernel.org. This vulnerability was named CVE-2026-68194 since 07/30/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. 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 08/10/2026).
Upgrading to version 6.6.148, 6.12.101, 6.18.42, 7.1.6 or 7.2-rc5 eliminates this vulnerability. Applying the patch ef2ee5f820c3ef87643b51e960c20b4a14d8336b/ecf995b828191829ba4a87169bccabcbeb5c9c32/263816e92e8d66c81c98ccab2b5d2191ed08ec71/24475d2ddc8d8dfd82f4d2be0d951401f86911a6/da4082e91acabc1498611ed8ccc53f0610baefc6 is able to eliminate this problem.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Product
Type
Vendor
Name
Version
- 6.0
- 6.1
- 6.2
- 6.3
- 6.4
- 6.5
- 6.6
- 6.6.147
- 6.7
- 6.8
- 6.9
- 6.10
- 6.11
- 6.12.100
- 6.18.0
- 6.18.1
- 6.18.2
- 6.18.3
- 6.18.4
- 6.18.5
- 6.18.6
- 6.18.7
- 6.18.8
- 6.18.9
- 6.18.10
- 6.18.11
- 6.18.12
- 6.18.13
- 6.18.14
- 6.18.15
- 6.18.16
- 6.18.17
- 6.18.18
- 6.18.19
- 6.18.20
- 6.18.21
- 6.18.22
- 6.18.23
- 6.18.24
- 6.18.25
- 6.18.26
- 6.18.27
- 6.18.28
- 6.18.29
- 6.18.30
- 6.18.31
- 6.18.32
- 6.18.33
- 6.18.34
- 6.18.35
- 6.18.36
- 6.18.37
- 6.18.38
- 6.18.39
- 6.18.40
- 6.18.41
- 7.1.0
- 7.1.1
- 7.1.2
- 7.1.3
- 7.1.4
- 7.1.5
- 7.2-rc1
- 7.2-rc2
- 7.2-rc3
- 7.2-rc4
License
Website
- Vendor: https://www.kernel.org/
CPE 2.3
CPE 2.2
CVSSv4
VulDB Vector: 🔒VulDB Reliability: 🔍
CVSSv3
VulDB Meta Base Score: 7.5VulDB Meta Temp Score: 7.2
VulDB Base Score: 7.5
VulDB Temp Score: 7.2
VulDB Vector: 🔒
VulDB Reliability: 🔍
CVSSv2
| AV | AC | Au | C | I | A |
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| 💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
| 💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
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| Vector | Complexity | Authentication | Confidentiality | Integrity | Availability |
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍
Exploiting
Class: Null pointer dereferenceCWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒
Physical: No
Local: No
Remote: Yes
Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒
| 0-Day | Unlock | Unlock | Unlock | Unlock |
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Threat Intelligence
Interest: 🔍Active Actors: 🔍
Active APT Groups: 🔍
Countermeasures
Recommended: UpgradeStatus: 🔍
0-Day Time: 🔒
Upgrade: Kernel 6.6.148/6.12.101/6.18.42/7.1.6/7.2-rc5
Patch: ef2ee5f820c3ef87643b51e960c20b4a14d8336b/ecf995b828191829ba4a87169bccabcbeb5c9c32/263816e92e8d66c81c98ccab2b5d2191ed08ec71/24475d2ddc8d8dfd82f4d2be0d951401f86911a6/da4082e91acabc1498611ed8ccc53f0610baefc6
Timeline
07/30/2026 CVE reserved08/10/2026 Advisory disclosed
08/10/2026 VulDB entry created
08/10/2026 VulDB entry last update
Sources
Vendor: kernel.orgAdvisory: git.kernel.org
Status: Confirmed
CVE: CVE-2026-68194 (🔒)
GCVE (CVE): GCVE-0-2026-68194
GCVE (VulDB): GCVE-100-387538
Entry
Created: 08/10/2026 15:55Changes: 08/10/2026 15:55 (59)
Complete: 🔍
Cache ID: 216::103
If you want to get best quality of vulnerability data, you may have to visit VulDB.
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