{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-23439", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-01-13T15:37:46.017Z", "datePublished": "2026-04-03T15:15:23.734Z", "dateUpdated": "2026-04-03T15:15:23.734Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-04-03T15:15:23.734Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nudp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n\n\nWhen CONFIG_IPV6 is disabled, the udp_sock_create6() function returns 0\n(success) without actually creating a socket. Callers such as\nfou_create() then proceed to dereference the uninitialized socket\npointer, resulting in a NULL pointer dereference.\n\nThe captured NULL deref crash:\n BUG: kernel NULL pointer dereference, address: 0000000000000018\n RIP: 0010:fou_nl_add_doit (net/ipv4/fou_core.c:590 net/ipv4/fou_core.c:764)\n [...]\n Call Trace:\n <TASK>\n genl_family_rcv_msg_doit.constprop.0 (net/netlink/genetlink.c:1114)\n genl_rcv_msg (net/netlink/genetlink.c:1194 net/netlink/genetlink.c:1209)\n [...]\n netlink_rcv_skb (net/netlink/af_netlink.c:2550)\n genl_rcv (net/netlink/genetlink.c:1219)\n netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)\n netlink_sendmsg (net/netlink/af_netlink.c:1894)\n __sock_sendmsg (net/socket.c:727 (discriminator 1) net/socket.c:742 (discriminator 1))\n __sys_sendto (./include/linux/file.h:62 (discriminator 1) ./include/linux/file.h:83 (discriminator 1) net/socket.c:2183 (discriminator 1))\n __x64_sys_sendto (net/socket.c:2213 (discriminator 1) net/socket.c:2209 (discriminator 1) net/socket.c:2209 (discriminator 1))\n do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1))\n entry_SYSCALL_64_after_hwframe (net/arch/x86/entry/entry_64.S:130)\n\nThis patch makes udp_sock_create6 return -EPFNOSUPPORT instead, so\ncallers correctly take their error paths. There is only one caller of\nthe vulnerable function and only privileged users can trigger it."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/net/udp_tunnel.h"], "versions": [{"version": "fd384412e199b62c3ddaabd18dce86d0e164c5b9", "lessThan": "ba7c9ddcdd077942b798979edb035207374d4096", "status": "affected", "versionType": "git"}, {"version": "fd384412e199b62c3ddaabd18dce86d0e164c5b9", "lessThan": "a05a2149386f6dfb4245f522acdbef892acafc84", "status": "affected", "versionType": "git"}, {"version": "fd384412e199b62c3ddaabd18dce86d0e164c5b9", "lessThan": "9f036aa0fe46c19e938f03d10e02c23f4fffae5e", "status": "affected", "versionType": "git"}, {"version": "fd384412e199b62c3ddaabd18dce86d0e164c5b9", "lessThan": "003343985f26dfefd0c94b1fe1316a2de74428b9", "status": "affected", "versionType": "git"}, {"version": "fd384412e199b62c3ddaabd18dce86d0e164c5b9", "lessThan": "12aa4b73a67d95bc739995a2d6943aec2f9785c9", "status": "affected", "versionType": "git"}, {"version": "fd384412e199b62c3ddaabd18dce86d0e164c5b9", "lessThan": "b3a6df291fecf5f8a308953b65ca72b7fc9e015d", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["include/net/udp_tunnel.h"], "versions": [{"version": "3.18", "status": "affected"}, {"version": "0", "lessThan": "3.18", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.167", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.130", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.78", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.20", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.19.10", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0-rc5", "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": "3.18", "versionEndExcluding": "6.1.167"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.18", "versionEndExcluding": "6.6.130"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.18", "versionEndExcluding": "6.12.78"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.18", "versionEndExcluding": "6.18.20"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.18", "versionEndExcluding": "6.19.10"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.18", "versionEndExcluding": "7.0-rc5"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/ba7c9ddcdd077942b798979edb035207374d4096"}, {"url": "https://git.kernel.org/stable/c/a05a2149386f6dfb4245f522acdbef892acafc84"}, {"url": "https://git.kernel.org/stable/c/9f036aa0fe46c19e938f03d10e02c23f4fffae5e"}, {"url": "https://git.kernel.org/stable/c/003343985f26dfefd0c94b1fe1316a2de74428b9"}, {"url": "https://git.kernel.org/stable/c/12aa4b73a67d95bc739995a2d6943aec2f9785c9"}, {"url": "https://git.kernel.org/stable/c/b3a6df291fecf5f8a308953b65ca72b7fc9e015d"}], "title": "udp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nudp_tunnel: fix NULL deref caused by udp_sock_create6 when CONFIG_IPV6=n\n\nWhen CONFIG_IPV6 is disabled, the udp_sock_create6() function returns 0\n(success) without actually creating a socket. Callers such as\nfou_create() then proceed to dereference the uninitialized socket\npointer, resulting in a NULL pointer dereference.\n\nThe captured NULL deref crash:\n BUG: kernel NULL pointer dereference, address: 0000000000000018\n RIP: 0010:fou_nl_add_doit (net/ipv4/fou_core.c:590 net/ipv4/fou_core.c:764)\n [...]\n Call Trace:\n <TASK>\n genl_family_rcv_msg_doit.constprop.0 (net/netlink/genetlink.c:1114)\n genl_rcv_msg (net/netlink/genetlink.c:1194 net/netlink/genetlink.c:1209)\n [...]\n netlink_rcv_skb (net/netlink/af_netlink.c:2550)\n genl_rcv (net/netlink/genetlink.c:1219)\n netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)\n netlink_sendmsg (net/netlink/af_netlink.c:1894)\n __sock_sendmsg (net/socket.c:727 (discriminator 1) net/socket.c:742 (discriminator 1))\n __sys_sendto (./include/linux/file.h:62 (discriminator 1) ./include/linux/file.h:83 (discriminator 1) net/socket.c:2183 (discriminator 1))\n __x64_sys_sendto (net/socket.c:2213 (discriminator 1) net/socket.c:2209 (discriminator 1) net/socket.c:2209 (discriminator 1))\n do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1))\n entry_SYSCALL_64_after_hwframe (net/arch/x86/entry/entry_64.S:130)\n\nThis patch makes udp_sock_create6 return -EPFNOSUPPORT instead, so\ncallers correctly take their error paths. There is only one caller of\nthe vulnerable function and only privileged users can trigger it."}], "id": "CVE-2026-23439", "lastModified": "2026-04-03T16:16:25.737", "metrics": {}, "published": "2026-04-03T16:16:25.737", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/003343985f26dfefd0c94b1fe1316a2de74428b9"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/12aa4b73a67d95bc739995a2d6943aec2f9785c9"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/9f036aa0fe46c19e938f03d10e02c23f4fffae5e"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a05a2149386f6dfb4245f522acdbef892acafc84"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/b3a6df291fecf5f8a308953b65ca72b7fc9e015d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/ba7c9ddcdd077942b798979edb035207374d4096"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{}

{}