{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-39965","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2025-04-16T07:20:57.149Z","datePublished":"2025-10-13T13:48:31.033Z","dateUpdated":"2026-08-05T12:06:34.191Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T12:06:34.191Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: xfrm_alloc_spi shouldn't use 0 as SPI\n\nx->id.spi == 0 means \"no SPI assigned\", but since commit\n94f39804d891 (\"xfrm: Duplicate SPI Handling\"), we now create states\nand add them to the byspi list with this value.\n\n__xfrm_state_delete doesn't remove those states from the byspi list,\nsince they shouldn't be there, and this shows up as a UAF the next\ntime we go through the byspi list."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerability is reached through the XFRM_MSG_ALLOCSPI message on a NETLINK_XFRM socket, which requires local system access. Although the dangling byspi entry can subsequently be dereferenced by a received ESP/AH packet, creating the SPI-0 state requires the local netlink path.\nAC:L - The attacker deterministically triggers the bug by requesting min=max=0, which verify_spi_info() accepts, then deleting the state via DELSA/FLUSHSA; there is no race, no memory-layout dependency, and no non-default config beyond ubiquitous CONFIG_XFRM_USER.\nPR:L - xfrm_user_rcv_msg() gates on netlink_net_capable(skb, CAP_NET_ADMIN), which is evaluated against the net namespace's user_ns, so any unprivileged user obtains it via \"unshare -Urn\". This is Low, not High.\nUI:N - The full sequence — allocate SPI 0, delete the state, re-walk the byspi hash — is performed entirely by the attacker's own process with no victim action required.\nS:U - The freed xfrm_state and the corrupted hash list both live in the kernel's own security authority; this is standard kernel memory corruption with no VM, IOMMU, or hypervisor boundary crossed.\nC:H - The dangling xfrm_state remains in a global RCU hash and is read back and returned as a live SA, so a reclaimed object leaks adjacent heap contents and crypto/key state, and the UAF can be escalated into an arbitrary kernel read primitive.\nI:H - Walkers perform refcount_inc_not_zero on the freed object (a write to freed memory) and then use it as a live SA whose type/mode function-pointer fields the attacker can control by re-spraying the xfrm_state slab, yielding control-flow hijack and arbitrary write.\nA:H - Dereferencing the freed state during byspi traversal, hash resize, or netns teardown (WARN_ON(!hlist_empty())) reliably produces a KASAN-detected use-after-free, list corruption, and kernel panic."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/xfrm/xfrm_state.c"],"versions":[{"version":"3d8090bb53424432fa788fe9a49e8ceca74f0544","lessThan":"0baf92d0b1590b903c1f4ead75e61715e50e8146","status":"affected","versionType":"git"},{"version":"2fc5b54368a1bf1d2d74b4d3b8eea5309a653e38","lessThan":"9fcedabaae0096f712bbb4ccca6a8538af1cd1c8","status":"affected","versionType":"git"},{"version":"29e9158f91f99057dbd35db5e8674d93b38549fe","lessThan":"a78e55776522373c446f18d5002a8de4b09e6bf7","status":"affected","versionType":"git"},{"version":"94f39804d891cffe4ce17737d295f3b195bc7299","lessThan":"cd8ae32e4e4652db55bce6b9c79267d8946765a9","status":"affected","versionType":"git"},{"version":"c67d4e7a8f90fb6361ca89d4d5c9a28f4e935e47","status":"affected","versionType":"git"},{"version":"6.15.11","lessThan":"6.16","status":"affected","versionType":"semver"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/xfrm/xfrm_state.c"],"versions":[{"version":"6.6.103","lessThan":"6.6.109","status":"affected","versionType":"semver"},{"version":"6.12.43","lessThan":"6.12.50","status":"affected","versionType":"semver"},{"version":"6.16.2","lessThan":"6.16.10","status":"affected","versionType":"semver"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.103","versionEndExcluding":"6.6.109"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12.43","versionEndExcluding":"6.12.50"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16.2","versionEndExcluding":"6.16.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15.11"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/0baf92d0b1590b903c1f4ead75e61715e50e8146"},{"url":"https://git.kernel.org/stable/c/9fcedabaae0096f712bbb4ccca6a8538af1cd1c8"},{"url":"https://git.kernel.org/stable/c/a78e55776522373c446f18d5002a8de4b09e6bf7"},{"url":"https://git.kernel.org/stable/c/cd8ae32e4e4652db55bce6b9c79267d8946765a9"}],"title":"xfrm: xfrm_alloc_spi shouldn't use 0 as SPI","x_generator":{"engine":"bippy-1.2.0"}}}}