CVE-2026-72157
HighCVSS 8.8Exploitation Probability (EPSS)
Low risk26th percentile - higher than 26% of all known CVEs
Summary
In the Linux kernel, the thunderbolt network driver (tbnet) lacks a bound on frame_count to the maximum number of skb fragments, leading to out-of-bounds write past frags[] and memory corruption. A malicious peer can send a packet with many small frames to trigger the overflow.
Risk Assessment
A remote attacker could cause kernel memory corruption, leading to system crash or potentially code execution.
Recommendation
Apply the Linux kernel patch that bounds frame_count to MAX_SKB_FRAGS + 1 to prevent frags[] overflow.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: net: thunderbolt: Fix frags[] overflow by bounding frame_count tbnet_poll() assembles a multi-frame ThunderboltIP packet into one skb. The first frame goes into the skb linear area and every further frame is added as a page fragment. skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, hdr_size, frame_size, TBNET_RX_PAGE_SIZE - hdr_size); A packet of frame_count frames therefore ends up with frame_count - 1 fragments. tbnet_check_frame() only bounds the peer supplied frame_count to TBNET_RING_SIZE / 4 (64), which is far above MAX_SKB_FRAGS (17 by default). A peer that sends a packet of 19 or more small frames pushes nr_frags past MAX_SKB_FRAGS, so skb_add_rx_frag() writes past skb_shinfo()->frags[] and corrupts memory after the shared info. Tighten the start of packet bound to MAX_SKB_FRAGS + 1 so a packet can never produce more fragments than frags[] can hold. This matches the recent skb frags overflow fixes in other receive paths, for example f0813bcd2d9d ("net: wwan: t7xx: fix potential skb->frags overflow in RX path") and 600dc40554dc ("net: usb: cdc-phonet: fix skb frags[] overflow in rx_complete()").