CVE-2026-64117: wifi: mac80211: capture fast-RX rate before mesh reuses skb->cb

Vulnerability summary

CVE-2026-64117 is a high (CVSS 8.8) Use After Free vulnerability in linux. EPSS estimates a 0.27% chance of exploitation in the next 30 days, higher than 18.5% of scored vulnerabilities.

Timeline

1. 19-07-2026
   PublishedVulnerability first disclosed.
2. 21-10-2026
   Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: capture fast-RX rate before mesh reuses skb->cb ieee80211_invoke_fast_rx() reads RX status through IEEE80211_SKB_RXCB(skb), which aliases the same skb->cb storage that ieee80211_rx_mesh_data() reuses as IEEE80211_TX_INFO. In the unicast forward path, mesh_data does: info = IEEE80211_SKB_CB(fwd_skb); memset(info, 0, sizeof(*info)); on the same skb the caller still names via rx->skb, then either queues the skb for TX (success) or kfree_skb()'s it (no-route) before returning RX_QUEUED. The caller's RX_QUEUED arm then calls sta_stats_encode_rate(status) on memory that is either zeroed (success path) or freed (no-route path). The latter is KASAN slab-use-after-free in ieee80211_prepare_and_rx_handle. Fix by encoding the rate from status before invoking ieee80211_rx_mesh_data(), so the RX_QUEUED arm consumes a value captured while status was still backed by valid memory.

• CWE-416Use After FreeThe product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.