cbcvebase.
CVE-2026-53240
published 2026-06-25

CVE-2026-53240: In the Linux kernel, the following vulnerability has been resolved: xfrm: iptfs: fix use-after-free on first_skb in __input_process_payload…

PriorityP350high8.8CVSS 3.1
AVNACLPRLUINSUCHIHAH
EPSS
0.42%
34.0th percentile
In the Linux kernel, the following vulnerability has been resolved: xfrm: iptfs: fix use-after-free on first_skb in __input_process_payload __input_process_payload() stores first_skb into xtfs->ra_newskb under drop_lock when starting partial reassembly, then unlocks and breaks out of the processing loop. The post-loop check reads xtfs->ra_newskb without the lock to decide whether first_skb is still owned: if (first_skb && first_iplen && !defer && first_skb != xtfs->ra_newskb) Between spin_unlock and this read, a concurrent CPU running iptfs_reassem_cont() (or the drop_timer hrtimer) can complete reassembly, NULL xtfs->ra_newskb, and free the skb. The check then evaluates first_skb != NULL as true, and pskb_trim/ip_summed/consume_skb operate on the freed skb — a use-after-free in skbuff_head_cache. Replace the unlocked read with a local bool that records whether first_skb was handed to the reassembly state in the current call. The flag is set after the existing spin_unlock, before the break, using the pointer equality that is stable at that point (first_skb == skb iff first_skb was stored in ra_newskb).

Affected

13 ranges
VendorProductVersion rangeFixed in
linuxlinux
linuxlinux>= 3f3339885fb343b7b42d7c34717108ce07da24ae < 8d9a79fbf5172d9c4c0146057af2360913265a118d9a79fbf5172d9c4c0146057af2360913265a11
linuxlinux>= 3f3339885fb343b7b42d7c34717108ce07da24ae < ff2ee35b6ce5fa8a8e24ea50b15733d5c8780198ff2ee35b6ce5fa8a8e24ea50b15733d5c8780198
linuxlinux>= 3f3339885fb343b7b42d7c34717108ce07da24ae < eb48730bb827d1550401a5d391903f9d90b493c8eb48730bb827d1550401a5d391903f9d90b493c8
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel>= 6.14 < 6.18.366.18.36
linuxlinux_kernel>= 6.19 < 7.0.137.0.13
Stop checking back — get the weekly exploitation signal.

Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.