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CVE-2026-90016
staging: rtl8723bs: fix OOB read in rtw_restruct_wmm_ie()
Published 2026-09-16 (33 days ago) by the Linux kernel CNA. Subsystem drivers/staging. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-90016 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | vulnerable | 6.1.190-1 | No fix published anywhere yet, neither in Debian nor upstream for the series bookworm tracks. Watch the Debian tracker page for this CVE. Advisories for bookworm have historically landed a median of 23 days after publication. |
| Debian 13trixie | fixedDSA-6568-1 · 2026-10-16 · text | 6.12.113-1 | Update the kernel and reboot. DSA-6568-1 shipped the fix on 2026-10-16, in 6.12.113-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.2.6-1 | Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.2.6-1 | Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
rtw_restruct_wmm_ie() scans in_ie for a WMM IE with: while (i < in_len) { ... if (i + 5 < in_len && in_ie[i] == 0xDD && ...) { ... break; } i += (in_ie[i + 1] + 2); /* to the next IE element */ } When the "i + 5 < in_len" match check fails simply because i is within 5 bytes of the end of the buffer (i.e. no WMM IE was found near the tail of in_ie), execution falls through to "i += (in_ie[i + 1] + 2)", which reads in_ie[i + 1]. If i == in_len - 1 at that point, this is a 1-byte out-of-bounds read of an attacker-influenced IE buffer built from association/scan data. Commit a75281626fc8f ("staging: rtl8723bs: fix potential out-of-bounds read in rtw_restruct_wmm_ie") added the "i + 5 < in_len" guard to the match condition itself, but did not add an equivalent guard before the fallthrough advance, so the same class of OOB read remained reachable through the non-matching path. Add an explicit bounds check before advancing to the next IE.
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
drivers/staging/rtl8723bs/core/rtw_mlme.c
- What this is
- STAGING SUBSYSTEMMAINTAINERS section matched on drivers/staging/ · linux-staging@lists.linux.dev · Supported
Show whether Debian builds this, per release
Not established. This site could not find the build rule for the affected file in the kernel trees Debian ships, so it has no answer about whether Debian compiles this code. Read that as unknown, never as absent.
- bookworm, trixie, forky, sid?
- ?
- not established - no Makefile entry for the affected file
Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS
Signals
- Published
- 2026-09-16 (33 days ago)source
- CVSS
- 7.1 high
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:Hsource recompute it - Attack vector
- adjacent network (AV:A)source
- EPSS
- 0.40%, higher than 32.4% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- drivers/staging
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 4.12 | 6.12.112 | e63b72c5d733 |
| 4.12 | 6.18.52 | 4420cc71841b |
| 4.12 | 7.2.5 | fd19b8895f8a |
| 4.12 | 7.3 | 28a289beaf22 |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DSA-6568-1 | 2026-10-16 | trixie 6.12.113-1 | tracker |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:AAttack vector, adjacent network
- rtw_restruct_wmm_ie() walks WMM IEs from scanned BSS candidates filled by collect_bss_info() from over-the-air beacon and probe-response frames (OnBeacon/OnProbeRsp). The attacker must be in WiFi radio range; kernel guidance maps WiFi frame injection to Adjacent.
- AC:LAttack complexity, low
- The attacker fully controls beacon/probe IE layout and can place a truncated tail IE so the walker lands at in_len-1, making the unguarded in_ie[i+1] read deterministic. wmm_enable defaults to 1, and no race or attacker-uncontrollable memory layout is required.
- PR:NPrivileges required, none
- Scan and join/roam consume attacker beacon IEs before any authentication with the rogue BSS. No local account, capability, or user-namespace privilege is required.
- UI:NUser interaction, none
- RTW_ROAM_ON_EXPIRED is enabled by default, so association expiry or an attacker-driven reconnect automatically calls rtw_select_and_join_from_scanned_queue() without a new victim click. An evil-twin BSS matching the desired SSID is selected by RSSI during normal WiFi operation.
- S:UScope, unchanged
- The out-of-bounds read and any resulting kernel impact remain inside the rtl8723bs driver on the host. This is not a VM escape, IOMMU bypass, or other cross-authority boundary crossing.
- C:LConfidentiality impact, low
- The fallthrough path reads exactly one byte past the declared IE length (in_ie[i+1] when i==in_len-1). Kernel guidance scores a strictly bounded few-byte out-of-bounds read as Low confidentiality rather than an arbitrary-read primitive.
- I:NIntegrity impact, none
- The bug only reads in_ie[i+1] to compute the next IE offset and then exits the loop. It does not write out of bounds or provide a data-modification or control-flow hijack primitive.
- A:HAvailability impact, high
- An out-of-bounds kernel read can oops or panic on hardened, KASAN, or redzone kernels, and an adjacent attacker can retrigger the join/roam path with further crafted management frames to deny availability.