CVE-2026-80943 wifi: rtlwifi: rtl8192du: check QoS TID before indexing tids
An out-of-bounds array access in the rtl8192du WiFi driver allows attackers to cause a denial of service via crafted QoS TID values.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-80943?
CVE-2026-80943 is a high-severity vulnerability in Linux, published on 11 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
wifi: rtlwifi: rtl8192du: check QoS TID before indexing tids
rtl92du_tx_fill_desc() uses ieee80211_get_tid() to read the QoS TID from the 802.11 header and then uses it as an index into sta_entry->tids[]. ieee80211_get_tid() returns the low 4-bit QoS TID value, so the result can be in the range 0..15.
rtlwifi only allocates MAX_TID_COUNT entries for sta_entry->tids[], and MAX_TID_COUNT is 9. A QoS TID greater than 8 therefore indexes past the aggregation state array. Keep the default RTL_AGG_STOP state for out-of-range TIDs, matching rtl92cu_tx_fill_desc().
This issue was detected by our static analysis tool and confirmed by manual audit. UBSAN validation for the same bug pattern reports an array-index-out-of-bounds access with index 10 for type 'rtl_tid_data [9]'.
Which versions are affected by CVE-2026-80943?
How do I fix CVE-2026-80943?
Apply the vendor's patch.
Is CVE-2026-80943 being exploited?
There is no known exploitation of CVE-2026-80943 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-80943, DEBIAN-CVE-2026-80943, GHSA-8f9m-rj4x-3w9p, UBUNTU-CVE-2026-80943.