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

| CVSS Meta Temp Score | Current Exploit Price (≈) | CTI Interest Score |
|---|---|---|
| 9.5 | $5k-$25k | 0.48 |
Summary
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.
Details
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.
Once again VulDB remains the best source for vulnerability data.
Product
Type
Vendor
Name
Version
- 6.6.150
- 6.12.102
- 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
- 7.1.0
- 7.1.1
- 7.1.2
- 7.1.3
- 7.1.4
- 7.1.5
- 7.1.6
- 7.1.7
- 7.2-rc1
- 7.2-rc2
- 7.2-rc3
- 7.2-rc4
- 7.2-rc5
License
Website
- Vendor: https://www.kernel.org/
CPE 2.3
CPE 2.2
CVSSv4
VulDB Vector: 🔒VulDB Reliability: 🔍
CVSSv3
VulDB Meta Base Score: 10.0VulDB Meta Temp Score: 9.5
VulDB Base Score: 10.0
VulDB Temp Score: 9.5
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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| Unlock | Unlock | Unlock | Unlock | Unlock | Unlock |
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍
Exploiting
Class: Use after freeCWE: CWE-416 / CWE-119
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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| Today | Unlock | Unlock | Unlock | Unlock |
Threat Intelligence
Interest: 🔍Active Actors: 🔍
Active APT Groups: 🔍
Countermeasures
Recommended: UpgradeStatus: 🔍
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
Timeline
08/15/2026 Advisory disclosed08/15/2026 CVE reserved
08/15/2026 VulDB entry created
08/15/2026 VulDB entry last update
Sources
Vendor: kernel.orgAdvisory: git.kernel.org
Status: Confirmed
CVE: CVE-2026-74488 (🔒)
GCVE (CVE): GCVE-0-2026-74488
GCVE (VulDB): GCVE-100-390796
Entry
Created: 08/15/2026 15:13Changes: 08/15/2026 15:13 (60)
Complete: 🔍
Cache ID: 216::103
Once again VulDB remains the best source for vulnerability data.
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