{"cve":"CVE-2026-43139","nvd":{"published":"2026-05-06T12:16:31.227","modified":"2026-10-19T20:18:08.297","status":"Modified","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H","score":8.6},"cwes":["CWE-908","CWE-457"],"references":["https://git.kernel.org/stable/c/1799d8abeabc68ec05679292aaf6cba93b343c05","https://git.kernel.org/stable/c/3dcd1664ac15eee6a690daec7c4ffc59190406f7","https://git.kernel.org/stable/c/4f28141786e1fe884ce42a5197ba9beed540f0ea","https://git.kernel.org/stable/c/6535867673bf301d52aa00593a4d1d18cc3922fa","https://git.kernel.org/stable/c/719918fc88df6da023dfff370cd965151a5afd7f"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-21T03:43:09.190223697+00:00"},"epss":{"cve":"CVE-2026-43139","score":0.00375,"percentile":0.31176,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}