{"id":"CVE-2026-98532","summary":"ipv6: do not let ipv6_find_hdr() return an offset past the packet end","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: do not let ipv6_find_hdr() return an offset past the packet end\n\nipv6_find_hdr() walks the extension header chain, skipping each header by\nthe length that header itself declares.  ipv6_optlen() returns up to 2048,\nand the skip is never checked against skb-\u003elen, so the offset stored in\n*offset can point past the end of the packet.\n\nopenvswitch installs that offset as the transport header, and\nupdate_ipv6_checksum() then reads and writes the transport checksum field\nout of bounds:\n\n  BUG: KASAN: slab-use-after-free in inet_proto_csum_replace16+0x445/0x470\n  Read of size 2 at addr ffff88810b754b06 by task ovs_ipv6_oob/629\n  CPU: 4 UID: 1000 PID: 629 Comm: ovs_ipv6_oob Tainted: G N 7.3.0-rc3+ #348\n  Call Trace:\n   inet_proto_csum_replace16+0x445/0x470\n   set_ipv6_addr+0x3dd/0x460\n   do_execute_actions+0x6a3d/0x7c40\n   ovs_execute_actions+0xfd/0x480\n   ovs_packet_cmd_execute+0xc38/0xf20\n   genl_rcv_msg+0x59e/0x870\n   netlink_rcv_skb+0x18b/0x450\n   genl_rcv+0x2d/0x40\n   netlink_unicast+0x6bc/0xa20\n\n  The buggy address belongs to the object at ffff88810b754980\n   which belongs to the cache skbuff_small_head of size 704\n  The buggy address is located 390 bytes inside of\n   freed 704-byte region [ffff88810b754980, ffff88810b754c40)\n\nOther callers use that offset too, so bound it here rather than in one\ncaller.\n\nReject a header whose declared length does not fit in the packet.\nipv6_find_hdr() already fails with -EBADMSG on a malformed chain, so this\nadds no new failure mode.","modified":"2026-10-19T02:46:29.497529619Z","published":"2026-10-18T15:17:50.490Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98532.json"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/1c70275ca87e769e1a52abc644d61372d8c016cb"},{"type":"WEB","url":"https://git.kernel.org/stable/c/1d42828565889632068fbc2983c34d57c66af4e0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4254d5878c320c19961dd0b8e1d0aca4800d8b7d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/531255de8971c06d5d5986f85fdc2525d707ba71"},{"type":"WEB","url":"https://git.kernel.org/stable/c/543354c6efb27eae3372a3a9674aeaa2a86e2b2c"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ca96b38730e31357ef4a9d76af1336958ac670d7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/dc92cb972e86790b8078337ec41015b748b8f8e5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ee319bd3a0e976af5087cbe59ebc50a66f31d202"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98532.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98532"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"f8f626754ebeca613cf1af2e6f890cfde0e74d5b"},{"fixed":"ca96b38730e31357ef4a9d76af1336958ac670d7"},{"fixed":"531255de8971c06d5d5986f85fdc2525d707ba71"},{"fixed":"543354c6efb27eae3372a3a9674aeaa2a86e2b2c"},{"fixed":"dc92cb972e86790b8078337ec41015b748b8f8e5"},{"fixed":"1c70275ca87e769e1a52abc644d61372d8c016cb"},{"fixed":"1d42828565889632068fbc2983c34d57c66af4e0"},{"fixed":"4254d5878c320c19961dd0b8e1d0aca4800d8b7d"},{"fixed":"ee319bd3a0e976af5087cbe59ebc50a66f31d202"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98532.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.8.0"},{"fixed":"5.10.271"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.222"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.189"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.158"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.112"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.55"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.9"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98532.json"}}],"schema_version":"1.9.0"}