{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-43139", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-05-01T14:12:55.988Z", "datePublished": "2026-05-06T11:27:24.898Z", "dateUpdated": "2026-08-05T12:26:11.398Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:26:11.398Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm6: fix uninitialized saddr in xfrm6_get_saddr()\n\nxfrm6_get_saddr() does not check the return value of\nipv6_dev_get_saddr(). When ipv6_dev_get_saddr() fails to find a suitable\nsource address (returns -EADDRNOTAVAIL), saddr->in6 is left\nuninitialized, but xfrm6_get_saddr() still returns 0 (success).\n\nThis causes the caller xfrm_tmpl_resolve_one() to use the uninitialized\naddress in xfrm_state_find(), triggering KMSAN warning:\n\n=====================================================\nBUG: KMSAN: uninit-value in xfrm_state_find+0x2424/0xa940\n xfrm_state_find+0x2424/0xa940\n xfrm_resolve_and_create_bundle+0x906/0x5a20\n xfrm_lookup_with_ifid+0xcc0/0x3770\n xfrm_lookup_route+0x63/0x2b0\n ip_route_output_flow+0x1ce/0x270\n udp_sendmsg+0x2ce1/0x3400\n inet_sendmsg+0x1ef/0x2a0\n __sock_sendmsg+0x278/0x3d0\n __sys_sendto+0x593/0x720\n __x64_sys_sendto+0x130/0x200\n x64_sys_call+0x332b/0x3e70\n do_syscall_64+0xd3/0xf80\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nLocal variable tmp.i.i created at:\n xfrm_resolve_and_create_bundle+0x3e3/0x5a20\n xfrm_lookup_with_ifid+0xcc0/0x3770\n=====================================================\n\nFix by checking the return value of ipv6_dev_get_saddr() and propagating\nthe error." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H", "baseScore": 8.6, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - A network-triggered path exists on an IPv6/IPsec endpoint: received IPv6 traffic that causes kernel-generated output, such as ICMPv6/NDISC replies or service responses, enters xfrm_lookup_route() and reaches xfrm_tmpl_resolve_one()->xfrm6_get_saddr(). The same code is locally reachable with sendmsg(), but a reasonably configured XFRM/IPsec host can be triggered by network traffic.\nAC:L - No race, heap grooming, or timing condition is required; once the affected outbound XFRM template has a wildcard IPv6 tunnel source and source address selection fails, the unchecked error path is deterministic. Matching output traffic can be triggered repeatedly.\nPR:N - The network trigger does not require the attacker to authenticate or hold local privileges. Creating the XFRM policy requires CAP_NET_ADMIN, including via a user/net namespace for local testing, but in the network scenario that policy is preexisting victim configuration.\nUI:N - No victim user action is required after the vulnerable XFRM/IPsec configuration is present. Packets or local sends directly drive the kernel output path.\nS:U - The bug affects kernel XFRM/IPv6 processing within the same host security authority. It does not cross a VM, IOMMU, or separate security scope boundary.\nC:L - The uninitialized value is a bounded 16-byte IPv6 source address from kernel stack, used in hashes/comparisons and potentially copied into XFRM acquire state/messages. This is limited kernel memory disclosure, not an arbitrary read primitive.\nI:L - The uninitialized source address can influence XFRM state lookup/acquire behavior and create or notify state using an unintended local tunnel endpoint. This is limited integrity impact to IPsec/XFRM state handling, not arbitrary modification.\nA:H - Syzbot reported a kernel BUG/KMSAN finding in xfrm_state_find(), and the bad value is consumed in core XFRM state lookup/acquire paths that can be triggered repeatedly. Kernel warning/oops/panic conditions are 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/xfrm6_policy.c" ], "versions": [ { "version": "a1e59abf824969554b90facd44a4ab16e265afa4", "lessThan": "4f28141786e1fe884ce42a5197ba9beed540f0ea", "status": "affected", "versionType": "git" }, { "version": "a1e59abf824969554b90facd44a4ab16e265afa4", "lessThan": "6535867673bf301d52aa00593a4d1d18cc3922fa", "status": "affected", "versionType": "git" }, { "version": "a1e59abf824969554b90facd44a4ab16e265afa4", "lessThan": "eb2ee15290af14c60b45cf2b73f5687d1d077d9b", "status": "affected", "versionType": "git" }, { "version": "a1e59abf824969554b90facd44a4ab16e265afa4", "lessThan": "719918fc88df6da023dfff370cd965151a5afd7f", "status": "affected", "versionType": "git" }, { "version": "a1e59abf824969554b90facd44a4ab16e265afa4", "lessThan": "dc0abce055134cb83b0d981d31ceb20dda419787", "status": "affected", "versionType": "git" }, { "version": "a1e59abf824969554b90facd44a4ab16e265afa4", "lessThan": "c7221e7bd8fc2ef38a0b27be580d9d202281306b", "status": "affected", "versionType": "git" }, { "version": "a1e59abf824969554b90facd44a4ab16e265afa4", "lessThan": "3dcd1664ac15eee6a690daec7c4ffc59190406f7", "status": "affected", "versionType": "git" }, { "version": "a1e59abf824969554b90facd44a4ab16e265afa4", "lessThan": "1799d8abeabc68ec05679292aaf6cba93b343c05", "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/ipv6/xfrm6_policy.c" ], "versions": [ { "version": "2.6.19", "status": "affected" }, { "version": "0", "lessThan": "2.6.19", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.252", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.202", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.165", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.128", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.75", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.16", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.6", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0", "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": "2.6.19", "versionEndExcluding": "5.10.252" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.19", "versionEndExcluding": "5.15.202" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.19", "versionEndExcluding": "6.1.165" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.19", "versionEndExcluding": "6.6.128" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.19", "versionEndExcluding": "6.12.75" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.19", "versionEndExcluding": "6.18.16" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.19", "versionEndExcluding": "6.19.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.19", "versionEndExcluding": "7.0" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/4f28141786e1fe884ce42a5197ba9beed540f0ea" }, { "url": "https://git.kernel.org/stable/c/6535867673bf301d52aa00593a4d1d18cc3922fa" }, { "url": "https://git.kernel.org/stable/c/eb2ee15290af14c60b45cf2b73f5687d1d077d9b" }, { "url": "https://git.kernel.org/stable/c/719918fc88df6da023dfff370cd965151a5afd7f" }, { "url": "https://git.kernel.org/stable/c/dc0abce055134cb83b0d981d31ceb20dda419787" }, { "url": "https://git.kernel.org/stable/c/c7221e7bd8fc2ef38a0b27be580d9d202281306b" }, { "url": "https://git.kernel.org/stable/c/3dcd1664ac15eee6a690daec7c4ffc59190406f7" }, { "url": "https://git.kernel.org/stable/c/1799d8abeabc68ec05679292aaf6cba93b343c05" } ], "title": "xfrm6: fix uninitialized saddr in xfrm6_get_saddr()", "x_generator": { "engine": "bippy-1.2.0" } } } }