{"id":"CVE-2026-43139","summary":"xfrm6: fix uninitialized saddr in xfrm6_get_saddr()","details":"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-\u003ein6 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.","modified":"2026-05-28T03:54:32.955980651Z","published":"2026-05-06T11:27:24.898Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43139.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/1799d8abeabc68ec05679292aaf6cba93b343c05"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3dcd1664ac15eee6a690daec7c4ffc59190406f7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4f28141786e1fe884ce42a5197ba9beed540f0ea"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6535867673bf301d52aa00593a4d1d18cc3922fa"},{"type":"WEB","url":"https://git.kernel.org/stable/c/719918fc88df6da023dfff370cd965151a5afd7f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c7221e7bd8fc2ef38a0b27be580d9d202281306b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/dc0abce055134cb83b0d981d31ceb20dda419787"},{"type":"WEB","url":"https://git.kernel.org/stable/c/eb2ee15290af14c60b45cf2b73f5687d1d077d9b"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43139.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43139"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"a1e59abf824969554b90facd44a4ab16e265afa4"},{"fixed":"4f28141786e1fe884ce42a5197ba9beed540f0ea"},{"fixed":"6535867673bf301d52aa00593a4d1d18cc3922fa"},{"fixed":"eb2ee15290af14c60b45cf2b73f5687d1d077d9b"},{"fixed":"719918fc88df6da023dfff370cd965151a5afd7f"},{"fixed":"dc0abce055134cb83b0d981d31ceb20dda419787"},{"fixed":"c7221e7bd8fc2ef38a0b27be580d9d202281306b"},{"fixed":"3dcd1664ac15eee6a690daec7c4ffc59190406f7"},{"fixed":"1799d8abeabc68ec05679292aaf6cba93b343c05"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-43139.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.6.19"},{"fixed":"5.10.252"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.202"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.165"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.128"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.75"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.16"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.6"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-43139.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H"}]}