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CVE-2026-64445
staging: rtl8723bs: fix WEP length underflow and OOB read in OnAuth()
Published 2026-07-25 (3 months 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-2026-64445 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 | fixedDLA-4720-1 · 2026-08-05 · text | 6.1.180-1 | Update the kernel and reboot. DLA-4720-1 shipped the fix on 2026-08-05, in 6.1.180-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixed | 6.12.96-1 | Update the kernel and reboot. Fixed in 6.12.96-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.1.4-1 | Update the kernel and reboot. Fixed in 7.1.4-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.4-1 | Update the kernel and reboot. Fixed in 7.1.4-1. A running kernel keeps the old code until the machine restarts. |
| Debian 12bookworm · linux-6.12 | fixedDLA-4724-1 · 2026-08-07 · text | 6.12.100-1~deb12u1 | Update the kernel and reboot. DLA-4724-1 shipped the fix on 2026-08-07, in 6.12.100-1~deb12u1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
OnAuth() has two bugs in the shared-key authentication path. When the Privacy bit is set, rtw_wep_decrypt() is called without verifying that the frame is long enough to contain a valid WEP IV and ICV. Inside rtw_wep_decrypt(), length is computed as: length = len - WLAN_HDR_A3_LEN - iv_len and then passed as (length - 4) to crc32_le(). If len is less than WLAN_HDR_A3_LEN + iv_len + icv_len (32 bytes), length - 4 is negative and, after the implicit cast to size_t, causes crc32_le() to read far beyond the frame buffer. Add a minimum length check before accessing the IV field and calling the decryption path. When processing a seq=3 response, rtw_get_ie() stores the Challenge Text IE length in ie_len, but the subsequent memcmp() always reads 128 bytes regardless of ie_len. IEEE 802.11 mandates a challenge text of exactly 128 bytes; reject any IE whose length field differs, matching the check already applied to OnAuthClient().
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_ext.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, bookworm · linux-6.12?
- ?
- 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
- 2026-07-25 (3 months ago)source
- CVSS
- 8.8 high
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- adjacent network (AV:A)source
- EPSS
- 0.32%, higher than 23.0% 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 | 5.10.261 | 665e1ecb68b4 |
| 4.12 | 5.15.212 | 87cccc2a767f |
| 4.12 | 6.1.178 | c9000c93078e |
| 4.12 | 6.6.145 | 1f6c9d255bdd |
| 4.12 | 6.12.96 | 3e44a7665f3a |
| 4.12 | 6.18.39 | 64ec4192d9c1 |
| 4.12 | 7.1.4 | d90b9f39f375 |
| 4.12 | 7.2 | a1fc19d61f66 |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DLA-4724-1 | 2026-08-07 | bookworm 6.12.100-1~deb12u1 | tracker |
| DLA-4723-1 | 2026-08-07 | bullseye 6.1.180-1~deb11u1 | tracker |
| DLA-4720-1 | 2026-08-05 | bookworm 6.1.180-1 | tracker |
| DLA-4717-1 | 2026-08-05 | bullseye 5.10.262-1 | 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
- A nearby attacker can inject crafted 802.11 authentication management frames over the wireless channel to an RTL8723BS interface operating in AP mode.
- AC:LAttack complexity, low
- A single attacker-controlled protected authentication frame can trigger the underflow without knowing a WEP key, winning a race, or satisfying conditions outside the attacker's control.
- PR:NPrivileges required, none
- The vulnerable decryption executes before authentication, association, MAC ACL enforcement, and authentication-algorithm validation, so no credentials or privileges are required.
- UI:NUser interaction, none
- Once the affected interface is operating normally in AP mode, exploitation requires no action by a victim user.
- S:UScope, unchanged
- The vulnerable driver and the affected kernel resources belong to the same operating-system security authority; this is not a guest-host or other scope-boundary escape.
- C:HConfidentiality impact, high
- The CRC underflow supplies a near-SIZE_MAX length to crc32_le(), producing a massive kernel out-of-bounds read, while the short-IE comparison can read up to 127 bytes beyond the Challenge Text IE.
- I:HIntegrity impact, high
- For protected frames shorter than 28 bytes, the negative signed length is converted to an approximately 4-GiB unsigned length for the in-place arc4_crypt(), causing extensive out-of-bounds writes capable of corrupting adjacent kernel heap state.
- A:HAvailability impact, high
- The enormous ARC4 operation or CRC read will cross the receive-buffer allocation and can cause an oops, panic, hang, or severe heap corruption; unauthenticated attackers can trigger this repeatedly.