{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-98838 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-98838 is a memory corruption vulnerability in Linux, published on 18 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-98838 and fix it if it is affected.\n\nWhat it is: CVE-2026-98838 is a memory corruption vulnerability in Linux, published on 18 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-98838 in the wild and no public exploit code.\n\nAffected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-98838/ (Markdown: https://insights.sbomify.com/CVE-2026-98838/index.md)","id":"CVE-2026-98838","markdown":"https://insights.sbomify.com/CVE-2026-98838/index.md","name":"CVE-2026-98838","record":{"aliases":["AZL-109248","BELL-CVE-2026-98838","DEBIAN-CVE-2026-98838","GHSA-798g-xwjp-798r","UBUNTU-CVE-2026-98838"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service","privilege_escalation"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A local attacker can trigger an out-of-bounds read in the Linux kernel VT subsystem via specific font operations, potentially causing a crash or privilege escalation.","user_interaction":"not_required","vuln_class":"memory_corruption"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":null,"severity":null,"source":null,"vector":null,"version":null},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nvt: skip screen update for DEC alignment test on backgroup consoles\n\n[BUG]\nRecently, we encountered a KASAN warning as follows:\n\nBUG: KASAN: slab-out-of-bounds in fb_pad_aligned_buffer+0x11f/0x140\nRead of size 1 at addr ff1100015fd9f6a4 by task tty_fbcon_oob/1239\nCPU: 7 UID: 0 PID: 1239 Comm: tty_fbcon_oob Not tainted 7.3.0-rc1 #100 PREEMPT(full)\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc41 04/01/2014\nCall Trace:\n \u003cTASK\u003e\n ...\n kasan_report+0xf0/0x120\n fb_pad_aligned_buffer+0x11f/0x140\n ccw_putcs+0x86c/0xa80\n fbcon_putcs+0x338/0x410\n do_update_region+0x21d/0x450\n do_con_write+0x1e0e/0x4880\n con_write+0x13/0x80\n n_tty_write+0x374/0x1010\n file_tty_write.isra.0+0x404/0x7a0\n ...\n\nreproduce:\n1) open /dev/tty0, set a KDFONTOP ioctl with op.op = KD_FONT_OP_SET,\nop.width = 8 and op.height = 16 (visible VC1)\n2) open /dev/tty1, set a KDFONTOP ioctl with op.op = KD_FONT_OP_SET,\nop.width = 28 and op.height = 24 (invisible VC2)\n3) echo 3 \u003e /sys/devices/virtual/graphics/fbcon/rotate_all\n4) write EShash8(esc hash8) to tty1\n\n[CAUSE]\nAll VCs render to the framebuffer. setfont only modifies the target VC's\nfont without resizing the framebuffer backing buffer (par-\u003erotated.buf);\nthe buffer is only resized for the visible VC\n(fbcon_do_set_font -\u003e ... -\u003e vc_do_resize -\u003e update_screen). This relies on\nthe con_should_update() check performed before every update_region().\n\nHowever, the ESC # 8 path (do_con_trol -\u003e do_update_region) omits the\ncon_should_update() check. After changing the font size of an invisible VC,\ndo_update_region() fills using the new font size against a buffer that was\nnever resized, causing an out-of-bounds access.\n\n[FIX]\nOnly push the update when the console is visible and not blanked, add\nthe con_should_update() check in the do_con_trol() like every other call\nsite of do_update_region() (update_region(), invert_screen(), ...).","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"vt: skip screen update for DEC alignment test on backgroup consoles","id":"CVE-2026-98838","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"memory_corruption","year":"2026"},"n_packages":0,"n_references":5,"next":{"headline":"vt: selection: Fix unsigned underflow and slab-out-of-bounds read in paste_selection()","id":"CVE-2026-98839"},"packages":[],"prev":{"headline":"ALSA: caiaq: unregister the input device when probe fails","id":"CVE-2026-98837"},"products":["Linux"],"published":"2026-10-18","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-10-21","vendors":["Linux"]},"summary":"A local attacker can trigger an out-of-bounds read in the Linux kernel VT subsystem via specific font operations, potentially causing a crash or privilege escalation.","url":"https://insights.sbomify.com/CVE-2026-98838/"}