CVE-2026-90017 staging: rtl8723bs: fix OOB read in rtw_action_frame_parse()
A missing length check in the rtl8723bs driver allows an attacker to trigger an out-of-bounds read, potentially disclosing kernel memory.
- 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-2026-90017?
CVE-2026-90017 is a high-severity vulnerability in Linux, published on 16 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:
staging: rtl8723bs: fix OOB read in rtw_action_frame_parse()
rtw_action_frame_parse() takes a frame_len parameter but never actually checks it before indexing into the frame body:
const u8 *frame_body = frame + sizeof(struct ieee80211_hdr_3addr); ... c = frame_body[0]; ... a = frame_body[1];
frame_body already points 24 bytes (sizeof(struct ieee80211_hdr_3addr)) into frame, so reading frame_body[0] and frame_body[1] requires frame_len >= 26. A management action frame shorter than that (e.g. exactly 24 bytes, the minimum a malicious peer can send) causes a 1-2 byte out-of-bounds read.
This is reachable from rtw_cfg80211_monitor_if_xmit_entry() and cfg80211_rtw_mgmt_tx() in ioctl_cfg80211.c, both of which pass attacker/user-influenced frame buffers and lengths straight through.
Add the missing length check before frame_body is dereferenced.
Which versions are affected by CVE-2026-90017?
How do I fix CVE-2026-90017?
Apply the vendor's patch.
Is CVE-2026-90017 being exploited?
There is no known exploitation of CVE-2026-90017 in the wild and no public exploit code.
Sources
Also known as AZL-101631, BELL-CVE-2026-90017, DEBIAN-CVE-2026-90017, GHSA-9fp4-x69f-gf9f, UBUNTU-CVE-2026-90017.