Linux Kernel up to 6.18.49/7.2.3 MT7996 Driver mt76_connac_txp_skb_unmap memory leak

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7.2	$0-$5k	0.00+

Summaryinfo

A vulnerability identified as critical has been detected in Linux Kernel up to 6.18.49/7.2.3. This affects the function mt76_connac_txp_skb_unmap of the component MT7996 Driver. The manipulation leads to memory leak. This vulnerability is referenced as CVE-2026-80934. Remote exploitation of the attack is possible. No exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.18.49/7.2.3. This issue affects the function mt76_connac_txp_skb_unmap of the component MT7996 Driver. The manipulation with an unknown input leads to a memory leak vulnerability. Using CWE to declare the problem leads to CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. Impacted is availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7996: fix TX DMA mapping leak for AddBA req frames mt7996/mt7992 hand the firmware a HW MAC-TXP for AddBA req action frames (MT_TXD7_MAC_TXD, set in mt7996_mac_write_txwi_80211()), but are otherwise FW-TXP devices. On tx free mt76_connac_txp_skb_unmap() therefore decodes the per-frame txp as a struct mt76_connac_fw_txp. For a MAC-TXP the fw_txp.nbuf byte aliases the AddBA TID word (MT_TXP1_TID_ADDBA), which is always zero, so the unmap loop runs zero times and the skb DMA mapping in buf[1] is never unmapped. buf[1].skip_unmap is set unconditionally, so the generic DMA-ring cleanup skips it as well. Each AddBA req therefore leaks one TX DMA mapping, roughly one per (re)association. With WED enabled these mappings are bounced through the WED swiotlb pool, so under continuous client reconnect churn the pool is exhausted after ~1-2 days, after which DMA mapping fails for WED, the WiFi MCU and other on-SoC consumers. Keep the deferred (token release) unmap that the design relies on, and add an mt7996-specific txp unmap that inspects MT_TXD7_MAC_TXD and unmaps buf[1] from the MAC-TXP layout for those frames, delegating to mt76_connac_txp_skb_unmap() otherwise.

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2026-80934 since 08/26/2026. 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 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 09/11/2026). The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

Upgrading to version 6.18.50, 7.2.4 or 7.3-rc1 eliminates this vulnerability. Applying the patch 01f2e0da8548f82d704b65b513026cfedc5f8962/b754d3a6d44c53d9853eba374d8a7ef279a9d00a/deaa2e3656937fbbe312f0ee2616c756c6e2511f is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 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
• 6.18.42
• 6.18.43
• 6.18.44
• 6.18.45
• 6.18.46
• 6.18.47
• 6.18.48
• 6.18.49
• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
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CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.2

VulDB Base Score: 7.5
VulDB Temp Score: 7.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
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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 6.18.50/7.2.4/7.3-rc1
Patch: 01f2e0da8548f82d704b65b513026cfedc5f8962/b754d3a6d44c53d9853eba374d8a7ef279a9d00a/deaa2e3656937fbbe312f0ee2616c756c6e2511f

Timelineinfo

08/26/2026 CVE reserved
09/11/2026 +16 days Advisory disclosed
09/11/2026 +0 days VulDB entry created
09/11/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-80934 (🔒)
GCVE (CVE): GCVE-0-2026-80934
GCVE (VulDB): GCVE-100-402635

Entryinfo

Created: 09/11/2026 23:11
Changes: 09/11/2026 23:11 (59)
Complete: 🔍
Cache ID: 216::103

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