{"id":"CVE-2026-64566","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: iptfs: propagate SKBFL_SHARED_FRAG in iptfs_skb_add_frags()\n\nWhen iptfs_skb_add_frags() copies frag references from the source\nfrag walk into a new SKB, it increm…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: iptfs: propagate SKBFL_SHARED_FRAG in iptfs_skb_add_frags()\n\nWhen iptfs_skb_add_frags() copies frag references from the source\nfrag walk into a new SKB, it increm…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","published":"2026-08-05","updated":"2026-08-08","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-64566","references":[{"url":"https://git.kernel.org/stable/c/430ea57d6daf765e88f90046afbfd1e071cb7200","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d8aaf06b29f5a0b6186cf68d21c7d63678ee3891","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ffd64e0717efd83fbf3396ab4e5ac6d795dac4d0","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd"],"epss":0.00352,"epssPercentile":0.28902,"ingestedAt":"2026-08-08T20:29:49.135Z","slug":"CVE-2026-64566","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: iptfs: propagate SKBFL_SHARED_FRAG in iptfs_skb_add_frags()\n\nWhen iptfs_skb_add_frags() copies frag references from the source\nfrag walk into a new SKB, it increments the page reference count via\n__skb_frag_ref() but does not propagate SKBFL_SHARED_FRAG to the\ndestination SKB's skb_shinfo->flags.\n\nIf the source SKB carries shared frags (e.g. from a page-pool backed\nreceive path), the new inner SKB will appear to ESP as having privately\nowned frags.  A subsequent esp_input() call for a nested transport-mode\nSA then takes the no-COW fast path and decrypts in place, writing over\npages that are still referenced by the outer IPTFS SKB.  This causes\nkernel-visible memory corruption and can trigger a panic.\n\nAll other frag-transfer helpers in the kernel (skb_try_coalesce,\nskb_gro_receive, __pskb_copy_fclone, skb_shift, skb_segment) correctly\npropagate SKBFL_SHARED_FRAG; align iptfs_skb_add_frags() with this\nconvention by setting the flag inside the loop immediately after\n__skb_frag_ref() and nr_frags++, so every exit path that attaches a frag\nunconditionally propagates SKBFL_SHARED_FRAG.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}