CVE-2026-98186 wifi: mwifiex: bound the pairwise-cipher OUI walk to the IE length
A crafted Wi-Fi beacon can cause an out-of-bounds read in the mwifiex driver, potentially leaking kernel memory or crashing the system.
- 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-2026-98186?
CVE-2026-98186 is a memory corruption vulnerability in Linux, published on 6 Oct 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: mwifiex: bound the pairwise-cipher OUI walk to the IE length
mwifiex_search_oui_in_ie() reads a pairwise-cipher (PTK) count from a beacon/probe-response RSN or WPA information element and then walks that many 4-byte OUIs, comparing each with memcmp(). The count comes straight from the (attacker-supplied) IE and is never checked against the element's own length, and the callers admit the element on element_id alone (has_ieee_hdr() / has_vendor_hdr(), no length check). A crafted RSN/WPA IE with a large pairwise count therefore makes the walk read up to 255 * 4 bytes past the element -- an out-of-bounds read of the kmemdup()'d beacon buffer, reachable from any AP whose beacon/probe response is processed during scan-result parsing.
Pass the number of IE bytes available at the OUI list and bound the walk to the element. Keep the length signed and reject a negative value before any unsigned arithmetic, so a small or zero IE length cannot underflow to a large size_t and defeat the bound.
Found by 0sec automated security-research tooling (https://0sec.ai).
Which versions are affected by CVE-2026-98186?
How do I fix CVE-2026-98186?
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-2026-98186 being exploited?
There is no known exploitation of CVE-2026-98186 in the wild and no public exploit code.
Sources
Also known as AZL-106134, BELL-CVE-2026-98186, DEBIAN-CVE-2026-98186, GHSA-vmvq-5qrr-gvg2, UBUNTU-CVE-2026-98186.