{ "cveId": "CVE-2026-98839", "url": "https://patchblox.com/security/cve/CVE-2026-98839", "summary": "CVE-2026-98839 is fixed in 20 products on 1 platform, first by DEBIAN-CVE-2026-98839, released October 19, 2026. It is not reported as exploited. Patch Radar priority: Routine.", "title": "vt: selection: Fix unsigned underflow and slab-out-of-bounds read in paste_selection()", "description": "In the Linux kernel, the following vulnerability has been resolved: vt: selection: Fix unsigned underflow and slab-out-of-bounds read in paste_selection() In paste_selection(), the loop copies min_t(unsigned int, vc_sel.buf_len - pasted,tty-\u003Ereceive_room) bytes per iteration into tty_ldisc_receive_buf() and increments pasted \u002B= count. Because the selection mutex (vc_sel.lock) is dropped inside the loop Whenever the line discipline buffer fills up and paste_selection() sleeps on tty-\u003Ewrite_wait, a concurrent TIOCLINUX (TIOCL_SETSEL) ioctl can replace vc_sel.buffer with a shorter selection and reduce vc_sel.buf_len below pasted. When paste_selection() resumes, vc_sel.buf_len - pasted underflows as an unsigned integer to a large positive value, causing tty_ldisc_receive_buf(ld, vc_sel.buffer \u002B pasted, NULL, count) to read up to 4094 bytes out-of-bounds past the newly allocated vc_sel.buffer. Fix this by terminating the loop when pasted \u003E= vc_sel.buf_len. Kernel stack trace (Linux 7.3.0-rc3): ================================================================== BUG: KASAN: slab-out-of-bounds in n_tty_receive_buf_common\u002B0xa01/0x1650 Read of size 4094 at addr ffff888101c58010 by task kworker/u17:1/65 Workqueue: events_unbound flush_to_ldisc Call Trace: \u003CTASK\u003E dump_stack_lvl\u002B0x70/0xa0 print_report\u002B0x153/0x4c6 kasan_report\u002B0xf1/0x120 kasan_check_range\u002B0x11c/0x200 __asan_memcpy\u002B0x29/0x70 n_tty_receive_buf_common\u002B0xa01/0x1650 tty_ldisc_receive_buf\u002B0x66/0x110 tty_port_default_receive_buf\u002B0x6b/0xb0 flush_to_ldisc\u002B0x1b4/0x410 process_one_work\u002B0x6ff/0x1110 worker_thread\u002B0x4a8/0xb70 kthread\u002B0x307/0x3e0 ret_from_fork\u002B0x3ed/0x680 \u003C/TASK\u003E ==================================================================", "published": "2026-10-18T16:17:38Z", "severity": "Low", "cvss": 3, "epss": 0.00166, "epssPercentile": 0.0586, "priority": "Routine", "priorityTier": 4, "exploited": false, "vendorExploited": false, "disclosed": false, "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-98839", "fixes": [ { "platform": "linux", "product": "bpftool6.18", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "bpftool6.18-debuginfo", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel-livepatch-6.18.56-125.164", "release": "amzn 2023", "fixedVersion": "1:1.0-0.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel6.18", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel6.18-debuginfo", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel6.18-debuginfo-common-aarch64", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel6.18-debuginfo-common-x86_64", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel6.18-devel", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel6.18-headers", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel6.18-modules-extra", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel6.18-modules-extra-common", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel6.18-tools", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel6.18-tools-debuginfo", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "kernel6.18-tools-devel", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "linux", "release": "Debian 14", "fixedVersion": "7.2.10-1", "fix": "DEBIAN-CVE-2026-98839", "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-98839", "released": "2026-10-19T16:27:52Z" }, { "platform": "linux", "product": "microvm-kernel6.18", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "perf6.18", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "perf6.18-debuginfo", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "python3-perf6.18", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" }, { "platform": "linux", "product": "python3-perf6.18-debuginfo", "release": "amzn 2023", "fixedVersion": "1:6.18.56-125.164.amzn2023", "fix": "ALAS2023-2026-3251", "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3251", "released": "2026-11-07T01:06:52Z" } ], "noFixYet": [], "dataAsOf": "2026-11-09T13:31:49Z", "attribution": { "text": "Data: Patchblox Patch Radar", "url": "https://patchblox.com/security/patch-radar", "terms": "https://patchblox.com/security/patch-radar/use-the-data" } }