{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64566","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-07-19T15:36:31.797Z","datePublished":"2026-08-05T08:06:18.645Z","dateUpdated":"2026-08-17T04:57:44.387Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-17T04:57:44.387Z"},"descriptions":[{"lang":"en","value":"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 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."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - The flaw is on the IPsec IPTFS receive path: inbound ESP packets hit xfrm_input → iptfs_input → iptfs_skb_add_frags, then reinjected inner packets reach nested transport-mode esp_input(); a remote IPTFS/IPsec peer triggers it with network packets.\nAC:L - On a host with IPTFS plus a nested transport-mode SA, the peer fully controls packet sizes and ESP payloads that take the frag-share path and drive in-place decrypt; no race or attacker-uncontrollable memory layout is required.\nPR:N - Exploitation is by a remote IPsec peer sending packets to an already-configured IPTFS endpoint; no local account or capability on the target is required, and SA presence is a deployment precondition rather than an attacker privilege.\nUI:N - Packets are processed in softirq/NAPI receive context with no victim action such as mounting, opening a file, or otherwise interacting with the system.\nS:U - Corruption is of shared skb/NIC fragment pages within the same kernel security authority; this is not a VM escape, IOMMU bypass, or cross-sandbox boundary crossing.\nC:H - Missing SKBFL_SHARED_FRAG lets nested esp_input() overwrite pages still referenced by the outer IPTFS skb and sibling inners, yielding attacker-influenced memory corruption that can be leveraged for information disclosure.\nI:H - In-place ESP decryption writes attacker-controlled plaintext into pages still held by other skbs, providing a memory-corruption write primitive capable of integrity compromise and control-flow impact.\nA:H - The same shared-page overwrite causes kernel-visible memory corruption and can panic/oops the host, fully denying availability."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/xfrm/xfrm_iptfs.c"],"versions":[{"version":"5f2b6a9095743a6bf1f34c43c4fe78fa8bdf5ad7","lessThan":"d8aaf06b29f5a0b6186cf68d21c7d63678ee3891","status":"affected","versionType":"git"},{"version":"5f2b6a9095743a6bf1f34c43c4fe78fa8bdf5ad7","lessThan":"ffd64e0717efd83fbf3396ab4e5ac6d795dac4d0","status":"affected","versionType":"git"},{"version":"5f2b6a9095743a6bf1f34c43c4fe78fa8bdf5ad7","lessThan":"430ea57d6daf765e88f90046afbfd1e071cb7200","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/xfrm/xfrm_iptfs.c"],"versions":[{"version":"6.14","status":"affected"},{"version":"0","lessThan":"6.14","status":"unaffected","versionType":"semver"},{"version":"6.18.42","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.6","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"6.18.42"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"7.1.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"7.2"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/d8aaf06b29f5a0b6186cf68d21c7d63678ee3891"},{"url":"https://git.kernel.org/stable/c/ffd64e0717efd83fbf3396ab4e5ac6d795dac4d0"},{"url":"https://git.kernel.org/stable/c/430ea57d6daf765e88f90046afbfd1e071cb7200"}],"title":"xfrm: iptfs: propagate SKBFL_SHARED_FRAG in iptfs_skb_add_frags()","x_generator":{"engine":"bippy-1.2.0"}}}}