{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-23003", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-01-13T15:37:45.939Z", "datePublished": "2026-01-25T14:36:17.491Z", "dateUpdated": "2026-08-05T12:20:05.561Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:20:05.561Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nip6_tunnel: use skb_vlan_inet_prepare() in __ip6_tnl_rcv()\n\nBlamed commit did not take care of VLAN encapsulations\nas spotted by syzbot [1].\n\nUse skb_vlan_inet_prepare() instead of pskb_inet_may_pull().\n\n[1]\n BUG: KMSAN: uninit-value in __INET_ECN_decapsulate include/net/inet_ecn.h:253 [inline]\n BUG: KMSAN: uninit-value in INET_ECN_decapsulate include/net/inet_ecn.h:275 [inline]\n BUG: KMSAN: uninit-value in IP6_ECN_decapsulate+0x7a8/0x1fa0 include/net/inet_ecn.h:321\n __INET_ECN_decapsulate include/net/inet_ecn.h:253 [inline]\n INET_ECN_decapsulate include/net/inet_ecn.h:275 [inline]\n IP6_ECN_decapsulate+0x7a8/0x1fa0 include/net/inet_ecn.h:321\n ip6ip6_dscp_ecn_decapsulate+0x16f/0x1b0 net/ipv6/ip6_tunnel.c:729\n __ip6_tnl_rcv+0xed9/0x1b50 net/ipv6/ip6_tunnel.c:860\n ip6_tnl_rcv+0xc3/0x100 net/ipv6/ip6_tunnel.c:903\n gre_rcv+0x1529/0x1b90 net/ipv6/ip6_gre.c:-1\n ip6_protocol_deliver_rcu+0x1c89/0x2c60 net/ipv6/ip6_input.c:438\n ip6_input_finish+0x1f4/0x4a0 net/ipv6/ip6_input.c:489\n NF_HOOK include/linux/netfilter.h:318 [inline]\n ip6_input+0x9c/0x330 net/ipv6/ip6_input.c:500\n ip6_mc_input+0x7ca/0xc10 net/ipv6/ip6_input.c:590\n dst_input include/net/dst.h:474 [inline]\n ip6_rcv_finish+0x958/0x990 net/ipv6/ip6_input.c:79\n NF_HOOK include/linux/netfilter.h:318 [inline]\n ipv6_rcv+0xf1/0x3c0 net/ipv6/ip6_input.c:311\n __netif_receive_skb_one_core net/core/dev.c:6139 [inline]\n __netif_receive_skb+0x1df/0xac0 net/core/dev.c:6252\n netif_receive_skb_internal net/core/dev.c:6338 [inline]\n netif_receive_skb+0x57/0x630 net/core/dev.c:6397\n tun_rx_batched+0x1df/0x980 drivers/net/tun.c:1485\n tun_get_user+0x5c0e/0x6c60 drivers/net/tun.c:1953\n tun_chr_write_iter+0x3e9/0x5c0 drivers/net/tun.c:1999\n new_sync_write fs/read_write.c:593 [inline]\n vfs_write+0xbe2/0x15d0 fs/read_write.c:686\n ksys_write fs/read_write.c:738 [inline]\n __do_sys_write fs/read_write.c:749 [inline]\n __se_sys_write fs/read_write.c:746 [inline]\n __x64_sys_write+0x1fb/0x4d0 fs/read_write.c:746\n x64_sys_call+0x30ab/0x3e70 arch/x86/include/generated/asm/syscalls_64.h:2\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xd3/0xf80 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nUninit was created at:\n slab_post_alloc_hook mm/slub.c:4960 [inline]\n slab_alloc_node mm/slub.c:5263 [inline]\n kmem_cache_alloc_node_noprof+0x9e7/0x17a0 mm/slub.c:5315\n kmalloc_reserve+0x13c/0x4b0 net/core/skbuff.c:586\n __alloc_skb+0x805/0x1040 net/core/skbuff.c:690\n alloc_skb include/linux/skbuff.h:1383 [inline]\n alloc_skb_with_frags+0xc5/0xa60 net/core/skbuff.c:6712\n sock_alloc_send_pskb+0xacc/0xc60 net/core/sock.c:2995\n tun_alloc_skb drivers/net/tun.c:1461 [inline]\n tun_get_user+0x1142/0x6c60 drivers/net/tun.c:1794\n tun_chr_write_iter+0x3e9/0x5c0 drivers/net/tun.c:1999\n new_sync_write fs/read_write.c:593 [inline]\n vfs_write+0xbe2/0x15d0 fs/read_write.c:686\n ksys_write fs/read_write.c:738 [inline]\n __do_sys_write fs/read_write.c:749 [inline]\n __se_sys_write fs/read_write.c:746 [inline]\n __x64_sys_write+0x1fb/0x4d0 fs/read_write.c:746\n x64_sys_call+0x30ab/0x3e70 arch/x86/include/generated/asm/syscalls_64.h:2\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xd3/0xf80 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nCPU: 0 UID: 0 PID: 6465 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(none)\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - __ip6_tnl_rcv() is reached from IPv6 packet receive via registered IPv6 tunnel/GRE protocol handlers, so a remote peer can trigger it by sending crafted tunneled IPv6/GRE packets to an exposed tunnel endpoint.\nAC:L - The attacker controls the tunneled packet format, including VLAN encapsulation, and there is no race or hard-to-hit timing condition.\nPR:N - Tunnel setup is privileged, but once the affected tunnel endpoint exists, the packet receive path has no attacker credential or authentication requirement.\nUI:N - Processing occurs automatically on packet receipt and does not require any victim user action.\nS:U - The bug affects kernel packet processing within the same host security authority and does not cross a VM, IOMMU, or sandbox boundary.\nC:N - The bug is an uninitialized value use in ECN decapsulation, but the investigated path does not expose the uninitialized kernel data to the attacker.\nI:N - The malformed packet can affect ECN/DSCP handling for that packet, but there is no evidence of arbitrary data modification or control-flow corruption.\nA:H - The reachable KMSAN BUG/oops path demonstrates that crafted packets can trigger a kernel fault condition, which is scored as high availability impact." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv6/ip6_tunnel.c" ], "versions": [ { "version": "a9bc32879a08f23cdb80a48c738017e39aea1080", "lessThan": "f9c5c5b791d3850570796f9e067629474e613796", "status": "affected", "versionType": "git" }, { "version": "af6b5c50d47ab43e5272ad61935d0ed2e264d3f0", "lessThan": "64c71d60a21a9ed0a802483dcd422b5b24eb1abe", "status": "affected", "versionType": "git" }, { "version": "d54e4da98bbfa8c257bdca94c49652d81d18a4d8", "lessThan": "9e1c8c2a33d0a7b1f637b5d0602fe56ed10166af", "status": "affected", "versionType": "git" }, { "version": "350a6640fac4b53564ec20aa3f4a0922cb0ba5e6", "lessThan": "2f03dafea0a8096a2eb60f551218b360e5bab9a3", "status": "affected", "versionType": "git" }, { "version": "8d975c15c0cd744000ca386247432d57b21f9df0", "lessThan": "df5ffde9669314500809bc498ae73d6d3d9519ac", "status": "affected", "versionType": "git" }, { "version": "8d975c15c0cd744000ca386247432d57b21f9df0", "lessThan": "b9f915340f25cae1562f18e1eb52deafca328414", "status": "affected", "versionType": "git" }, { "version": "8d975c15c0cd744000ca386247432d57b21f9df0", "lessThan": "81c734dae203757fb3c9eee6f9896386940776bd", "status": "affected", "versionType": "git" }, { "version": "c835df3bcc14858ae9b27315dd7de76370b94f3a", "status": "affected", "versionType": "git" }, { "version": "5.10.210", "lessThan": "5.10.249", "status": "affected", "versionType": "semver" }, { "version": "5.15.149", "lessThan": "5.15.199", "status": "affected", "versionType": "semver" }, { "version": "6.1.77", "lessThan": "6.1.162", "status": "affected", "versionType": "semver" }, { "version": "6.6.16", "lessThan": "6.6.122", "status": "affected", "versionType": "semver" }, { "version": "6.7.4", "lessThan": "6.8", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/ipv6/ip6_tunnel.c" ], "versions": [ { "version": "6.8", "status": "affected" }, { "version": "0", "lessThan": "6.8", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.249", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.199", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.162", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.122", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.67", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.7", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19", "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": "5.10.210", "versionEndExcluding": "5.10.249" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.149", "versionEndExcluding": "5.15.199" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1.77", "versionEndExcluding": "6.1.162" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.6.16", "versionEndExcluding": "6.6.122" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "6.12.67" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "6.18.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "6.19" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.7.4" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/f9c5c5b791d3850570796f9e067629474e613796" }, { "url": "https://git.kernel.org/stable/c/64c71d60a21a9ed0a802483dcd422b5b24eb1abe" }, { "url": "https://git.kernel.org/stable/c/9e1c8c2a33d0a7b1f637b5d0602fe56ed10166af" }, { "url": "https://git.kernel.org/stable/c/2f03dafea0a8096a2eb60f551218b360e5bab9a3" }, { "url": "https://git.kernel.org/stable/c/df5ffde9669314500809bc498ae73d6d3d9519ac" }, { "url": "https://git.kernel.org/stable/c/b9f915340f25cae1562f18e1eb52deafca328414" }, { "url": "https://git.kernel.org/stable/c/81c734dae203757fb3c9eee6f9896386940776bd" } ], "title": "ip6_tunnel: use skb_vlan_inet_prepare() in __ip6_tnl_rcv()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2026-06-16T20:17:50.477974Z", "id": "CVE-2026-23003", "options": [ { "Exploitation": "none" }, { "Automatable": "yes" }, { "Technical Impact": "partial" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-06-16T20:18:00.168Z" } }, { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-07-14T12:45:43.294Z" }, "affected": [ { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" } ], "references": [ { "url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html" } ] } ] } }