{"id":"CVE-2026-43407","title":"libceph: Fix potential out-of-bounds access in ceph_handle_auth_reply()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: Fix potential out-of-bounds access in ceph_handle_auth_reply()\n\nThis patch fixes an out-of-bounds access in ceph_handle_auth_reply()\nthat can be triggered by a…","severity":"critical","cvss":9.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 4e7a5dcd1bbab6560fbc8ada29a840e7a20ed7bc < ea080b21092590122c3f971cf588932cdbf47847","Linux >= 4e7a5dcd1bbab6560fbc8ada29a840e7a20ed7bc < edc678e5cd11730a2834b43071d8923f05bc334d","Linux >= 4e7a5dcd1bbab6560fbc8ada29a840e7a20ed7bc < 6cee34d6669fe176b4259131adb1a145c939b472","Linux >= 4e7a5dcd1bbab6560fbc8ada29a840e7a20ed7bc < 8bb87547e92dcf0928ed763c60e0ac8d733c3656","Linux >= 4e7a5dcd1bbab6560fbc8ada29a840e7a20ed7bc < ed024d2f4c79c0eb2464df0fb640610ac301f9a0","Linux >= 4e7a5dcd1bbab6560fbc8ada29a840e7a20ed7bc < f9da5c1bbac5c8e33259fe00ed7347438fffa969","Linux >= 4e7a5dcd1bbab6560fbc8ada29a840e7a20ed7bc < 9f9e2297f45fc2d2524eb104c289d69ddef95665","Linux >= 4e7a5dcd1bbab6560fbc8ada29a840e7a20ed7bc < b282c43ed156ae15ea76748fc15cd5c39dc9ab72","Linux 2.6.34"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-10-16T15:17:11.997253Z"},"published":"2026-05-08","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:20:41.235Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-43407","references":[{"url":"https://git.kernel.org/stable/c/ea080b21092590122c3f971cf588932cdbf47847"},{"url":"https://git.kernel.org/stable/c/edc678e5cd11730a2834b43071d8923f05bc334d"},{"url":"https://git.kernel.org/stable/c/6cee34d6669fe176b4259131adb1a145c939b472"},{"url":"https://git.kernel.org/stable/c/8bb87547e92dcf0928ed763c60e0ac8d733c3656"},{"url":"https://git.kernel.org/stable/c/ed024d2f4c79c0eb2464df0fb640610ac301f9a0"},{"url":"https://git.kernel.org/stable/c/f9da5c1bbac5c8e33259fe00ed7347438fffa969"},{"url":"https://git.kernel.org/stable/c/9f9e2297f45fc2d2524eb104c289d69ddef95665"},{"url":"https://git.kernel.org/stable/c/b282c43ed156ae15ea76748fc15cd5c39dc9ab72"}],"tags":["cve.org"],"epss":0.00537,"epssPercentile":0.44003,"ingestedAt":"2026-10-16T17:24:46.695Z","slug":"CVE-2026-43407","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: Fix potential out-of-bounds access in ceph_handle_auth_reply()\n\nThis patch fixes an out-of-bounds access in ceph_handle_auth_reply()\nthat can be triggered by a message of type CEPH_MSG_AUTH_REPLY. In\nceph_handle_auth_reply(), the value of the payload_len field of such a\nmessage is stored in a variable of type int. A value greater than\nINT_MAX leads to an integer overflow and is interpreted as a negative\nvalue. This leads to decrementing the pointer address by this value and\nsubsequently accessing it because ceph_decode_need() only checks that\nthe memory access does not exceed the end address of the allocation.\n\nThis patch fixes the issue by changing the data type of payload_len to\nu32. Additionally, the data type of result_msg_len is changed to u32,\nas it is also a variable holding a non-negative length.\n\nAlso, an additional layer of sanity checks is introduced, ensuring that\ndirectly after reading it from the message, payload_len and\nresult_msg_len are not greater than the overall segment length.\n\nBUG: KASAN: slab-out-of-bounds in ceph_handle_auth_reply+0x642/0x7a0 [libceph]\nRead of size 4 at addr ffff88811404df14 by task kworker/20:1/262\n\nCPU: 20 UID: 0 PID: 262 Comm: kworker/20:1 Not tainted 6.19.2 #5 PREEMPT(voluntary)\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014\nWorkqueue: ceph-msgr ceph_con_workfn [libceph]\nCall Trace:\n <TASK>\n dump_stack_lvl+0x76/0xa0\n print_report+0xd1/0x620\n ? __pfx__raw_spin_lock_irqsave+0x10/0x10\n ? kasan_complete_mode_report_info+0x72/0x210\n kasan_report+0xe7/0x130\n ? ceph_handle_auth_reply+0x642/0x7a0 [libceph]\n ? ceph_handle_auth_reply+0x642/0x7a0 [libceph]\n __asan_report_load_n_noabort+0xf/0x20\n ceph_handle_auth_reply+0x642/0x7a0 [libceph]\n mon_dispatch+0x973/0x23d0 [libceph]\n ? apparmor_socket_recvmsg+0x6b/0xa0\n ? __pfx_mon_dispatch+0x10/0x10 [libceph]\n ? __kasan_check_write+0x14/0x30i\n ? mutex_unlock+0x7f/0xd0\n ? __pfx_mutex_unlock+0x10/0x10\n ? __pfx_do_recvmsg+0x10/0x10 [libceph]\n ceph_con_process_message+0x1f1/0x650 [libceph]\n process_message+0x1e/0x450 [libceph]\n ceph_con_v2_try_read+0x2e48/0x6c80 [libceph]\n ? __pfx_ceph_con_v2_try_read+0x10/0x10 [libceph]\n ? save_fpregs_to_fpstate+0xb0/0x230\n ? raw_spin_rq_unlock+0x17/0xa0\n ? finish_task_switch.isra.0+0x13b/0x760\n ? __switch_to+0x385/0xda0\n ? __kasan_check_write+0x14/0x30\n ? mutex_lock+0x8d/0xe0\n ? __pfx_mutex_lock+0x10/0x10\n ceph_con_workfn+0x248/0x10c0 [libceph]\n process_one_work+0x629/0xf80\n ? __kasan_check_write+0x14/0x30\n worker_thread+0x87f/0x1570\n ? __pfx__raw_spin_lock_irqsave+0x10/0x10\n ? __pfx_try_to_wake_up+0x10/0x10\n ? kasan_print_address_stack_frame+0x1f7/0x280\n ? __pfx_worker_thread+0x10/0x10\n kthread+0x396/0x830\n ? __pfx__raw_spin_lock_irq+0x10/0x10\n ? __pfx_kthread+0x10/0x10\n ? __kasan_check_write+0x14/0x30\n ? recalc_sigpending+0x180/0x210\n ? __pfx_kthread+0x10/0x10\n ret_from_fork+0x3f7/0x610\n ? __pfx_ret_from_fork+0x10/0x10\n ? __switch_to+0x385/0xda0\n ? __pfx_kthread+0x10/0x10\n ret_from_fork_asm+0x1a/0x30\n </TASK>\n\n[ idryomov: replace if statements with ceph_decode_need() for\n  payload_len and result_msg_len ]\n\n## Affected\n\n- `Linux >= 4e7a5dcd1bbab6560fbc8ada29a840e7a20ed7bc < ea080b21092590122c3f971cf588932cdbf47847`\n- `Linux >= 4e7a5dcd1bbab6560fbc8ada29a840e7a20ed7bc < edc678e5cd11730a2834b43071d8923f05bc334d`\n- `Linux >= 4e7a5dcd1bbab6560fbc8ada29a840e7a20ed7bc < 6cee34d6669fe176b4259131adb1a145c939b472`\n- `Linux >= 4e7a5dcd1bbab6560fbc8ada29a840e7a20ed7bc < 8bb87547e92dcf0928ed763c60e0ac8d733c3656`\n- `Linux >= 4e7a5dcd1bbab6560fbc8ada29a840e7a20ed7bc < ed024d2f4c79c0eb2464df0fb640610ac301f9a0`\n- `Linux >= 4e7a5dcd1bbab6560fbc8ada29a840e7a20ed7bc < f9da5c1bbac5c8e33259fe00ed7347438fffa969`\n- `Linux >= 4e7a5dcd1bbab6560fbc8ada29a840e7a20ed7bc < 9f9e2297f45fc2d2524eb104c289d69ddef95665`\n- `Linux >= 4e7a5dcd1bbab6560fbc8ada29a840e7a20ed7bc < b282c43ed156ae15ea76748fc15cd5c39dc9ab72`\n- `Linux 2.6.34`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":50,"depthScoreParts":{"impact":50.1,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}