CVE-2026-72057
In the Linux kernel, the following vulnerability has been resolved: net/sched: act_ct: preserve tc_skb_cb across defragmentation tcf_ct_handle_fragments() calls nf_ct_handle_fragments() without saving and restoring skb->cb.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.58%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
In the Linux kernel, the following vulnerability has been resolved: net/sched: act_ct: preserve tc_skb_cb across defragmentation tcf_ct_handle_fragments() calls nf_ct_handle_fragments() without saving and restoring skb->cb. The defrag helper clears IPCB/IP6CB, which aliases the tc_skb_cb/qdisc_skb_cb control buffer. Fragmented traffic through act_ct therefore loses qdisc metadata such as pkt_segs and can trigger WARN_ON_ONCE() in qdisc_pkt_segs() when panic_on_warn is enabled. Save and restore the full tc_skb_cb around nf_ct_handle_fragments(), matching the pattern used by ovs_ct_handle_fragments().
- CVSS 3.1
- 8.2 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
- EPSS
- 0.58% probability · 46th percentile
- CISA KEV
- Not listed
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/2400c4b05d58834b994500a9eec90a37db44187c
- https://git.kernel.org/stable/c/5c3ae5f6c7c6de73ea9b6a75154fe4ed343e1bac
- https://git.kernel.org/stable/c/67d6b00a54446c008f52cf70fc0c2ad0c712f85d
- https://git.kernel.org/stable/c/9092e15defbe6c7bc241c306093ca9d358a578e7
- https://git.kernel.org/stable/c/b3d835407846134b0d54637c0281b39bebef831d
- https://git.kernel.org/stable/c/f7f45ceb855d9ba1cba594fb3f383255f7013fad
- https://git.kernel.org/stable/c/fb080b6f54835d5d4d11ce3122800e6f0f6689e6
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.