CVE-2026-74649 staging: rtl8723bs: fix missing shared-key auth challenge length check
A malicious access point can trigger a buffer overflow or leak memory in the rtl8723bs Wi-Fi driver during shared-key authentication, potentially leading to code execution or data disclosure.
- 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-2026-74649?
CVE-2026-74649 is a high-severity memory corruption vulnerability in Linux, published on 22 Aug 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 missing shared-key auth challenge length check
The WEP shared-key authentication handler uses the challenge-text element's attacker-controlled length without checking it against the fixed 128-byte chg_txt buffer.
In OnAuthClient() the length from rtw_get_ie() - up to 255 - is used to perform memcpy() into the 128-byte pmlmeinfo->chg_txt, so a malicious AP sending a malformed WLAN_EID_CHALLENGE element can overflow/underfill chg_txt by up to 127 bytes. It is reachable over the air, before association, during shared-key authentication. In the case of an overflow, the driver can write out of bounds. In the case of an underfill, the driver can echo stale buffer memory.
The challenge text is defined to be exactly 128 octets, which is already provided as the WLAN_AUTH_CHALLENGE_LEN define; require the element to be exactly that length before use.
Which versions are affected by CVE-2026-74649?
How do I fix CVE-2026-74649?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-74649 being exploited?
There is no known exploitation of CVE-2026-74649 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-74649, DEBIAN-CVE-2026-74649, GHSA-3j7p-mfvr-mgx3, UBUNTU-CVE-2026-74649.