Linux Kernel up to 7.2-rc5 mwifiex mwifiex_11n_dispatch_amsdu_pkt len use after free

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CTI Interest Score
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9.5$5k-$25k0.48

Summaryinfo

A vulnerability classified as very critical was found in Linux Kernel up to 6.6.150/6.12.102/6.18.43/7.1.7/7.2-rc5. Affected is the function mwifiex_11n_dispatch_amsdu_pkt of the component mwifiex. Executing a manipulation of the argument len can lead to use after free. This vulnerability is handled as CVE-2026-74488. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.150/6.12.102/6.18.43/7.1.7/7.2-rc5. It has been declared as very critical. This vulnerability affects the function mwifiex_11n_dispatch_amsdu_pkt of the component mwifiex. The manipulation of the argument len 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: wifi: mwifiex: use the subframe length when parsing A-MSDU TDLS frames mwifiex_11n_dispatch_amsdu_pkt() splits an A-MSDU with ieee80211_amsdu_to_8023s() and walks the resulting subframes. For each subframe it passes the subframe data pointer to mwifiex_process_tdls_action_frame(), but pairs it with skb->len, the length of the A-MSDU parent, instead of rx_skb->len: rx_skb = __skb_dequeue(&list); rx_hdr = (struct rx_packet_hdr *)rx_skb->data; if (ISSUPP_TDLS_ENABLED(priv->adapter->fw_cap_info) && ntohs(rx_hdr->eth803_hdr.h_proto) == ETH_P_TDLS) { mwifiex_process_tdls_action_frame(priv, (u8 *)rx_hdr, skb->len); } The parent is not a valid description of that buffer, and may not be valid memory at all. ieee80211_amsdu_to_8023s() ends with if (!reuse_skb) dev_kfree_skb(skb); and it only sets reuse_skb when the parent is linear, is not a head_frag, and is being consumed as the *last* subframe. So when the parent does not qualify for reuse it has already been freed, and the read of skb->len is a use-after-free. When it is reused, skb->len is the length of the last subframe, applied to every earlier subframe, which over-states the buffer whenever an earlier subframe is shorter. The callee cannot absorb a wrong length, because it derives its own ceiling from the value it is given. Each frame type computes ies_len = len - sizeof(struct ethhdr) - TDLS_*_FIX_LEN; and the element walk is then bounded entirely against that ceiling, for (end = pos + ies_len; pos + 1 < end; pos += 2 + pos[1]) { u8 ie_len = pos[1]; if (pos + 2 + ie_len > end) break; so a too-large len moves end past the end of the subframe and the walk reads and copies beyond it. The A-MSDU layout is chosen by the sender, which makes the difference between the last subframe and a shorter earlier one remotely selectable. Reaching this requires TDLS support in firmware and the TDLS ethertype on the subframe. The other caller, mwifiex_process_rx_packet(), is correct: it passes a pointer and a length that describe the same region of the RX buffer. Pass rx_skb->len, the length of the subframe actually being parsed.

The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2026-74488 since 08/15/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 08/15/2026).

Upgrading to version 6.6.151, 6.12.103, 6.18.44, 7.1.8 or 7.2-rc6 eliminates this vulnerability. Applying the patch 25e5a3fe4f15e30f74eca42cbf3bcc3a3fbeda79/ece2ebb34247d573142617dfc534a9dc11ba59be/c9dcfe6b8b71369e1d732e2ff622c3696a2f032c/5a21ab03829cb6d2682c127f22e2b9cd63b4393f/99a948382af8a225e2d5e54a7052158cd6281cc6 is able to eliminate this problem.

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Productinfo

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Version

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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 6.6.151/6.12.103/6.18.44/7.1.8/7.2-rc6
Patch: 25e5a3fe4f15e30f74eca42cbf3bcc3a3fbeda79/ece2ebb34247d573142617dfc534a9dc11ba59be/c9dcfe6b8b71369e1d732e2ff622c3696a2f032c/5a21ab03829cb6d2682c127f22e2b9cd63b4393f/99a948382af8a225e2d5e54a7052158cd6281cc6

Timelineinfo

08/15/2026 Advisory disclosed
08/15/2026 +0 days CVE reserved
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-2026-74488 (🔒)
GCVE (CVE): GCVE-0-2026-74488
GCVE (VulDB): GCVE-100-390796

Entryinfo

Created: 08/15/2026 15:13
Changes: 08/15/2026 15:13 (60)
Complete: 🔍
Cache ID: 216::103

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