{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-23121 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-23121 is a medium-severity vulnerability in Linux kernel, published on 14 Feb 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-2026-23121 and fix it if it is affected.\n\nWhat it is: CVE-2026-23121 is a medium-severity vulnerability in Linux kernel, published on 14 Feb 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-2026-23121 in the wild and no public exploit code.\n\nAffected product: Linux kernel. 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-2026-23121/ (Markdown: https://insights.sbomify.com/CVE-2026-23121/index.md)","id":"CVE-2026-23121","markdown":"https://insights.sbomify.com/CVE-2026-23121/index.md","name":"CVE-2026-23121","record":{"aliases":["AZL-77793","BELL-CVE-2026-23121","DEBIAN-CVE-2026-23121","GHSA-h3v4-524h-5jpx","ROOT-OS-UBUNTU-2204-CVE-2026-23121","ROOT-OS-UBUNTU-2404-CVE-2026-23121","UBUNTU-CVE-2026-23121"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["other"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A data race in the Linux kernel mISDN driver can lead to undefined behavior, requiring kernel patching to ensure thread safety.","user_interaction":"not_required","vuln_class":"race_condition"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":5.5,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-362","name":"Concurrent Execution using Shared Resource with Improper Synchronization"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmISDN: annotate data-race around dev-\u003ework\n\ndev-\u003ework can re read locklessly in mISDN_read()\nand mISDN_poll(). Add READ_ONCE()/WRITE_ONCE() annotations.\n\nBUG: KCSAN: data-race in mISDN_ioctl / mISDN_read\n\nwrite to 0xffff88812d848280 of 4 bytes by task 10864 on cpu 1:\n  misdn_add_timer drivers/isdn/mISDN/timerdev.c:175 [inline]\n  mISDN_ioctl+0x2fb/0x550 drivers/isdn/mISDN/timerdev.c:233\n  vfs_ioctl fs/ioctl.c:51 [inline]\n  __do_sys_ioctl fs/ioctl.c:597 [inline]\n  __se_sys_ioctl+0xce/0x140 fs/ioctl.c:583\n  __x64_sys_ioctl+0x43/0x50 fs/ioctl.c:583\n  x64_sys_call+0x14b0/0x3000 arch/x86/include/generated/asm/syscalls_64.h:17\n  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n  do_syscall_64+0xd8/0x2c0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nread to 0xffff88812d848280 of 4 bytes by task 10857 on cpu 0:\n  mISDN_read+0x1f2/0x470 drivers/isdn/mISDN/timerdev.c:112\n  do_loop_readv_writev fs/read_write.c:847 [inline]\n  vfs_readv+0x3fb/0x690 fs/read_write.c:1020\n  do_readv+0xe7/0x210 fs/read_write.c:1080\n  __do_sys_readv fs/read_write.c:1165 [inline]\n  __se_sys_readv fs/read_write.c:1162 [inline]\n  __x64_sys_readv+0x45/0x50 fs/read_write.c:1162\n  x64_sys_call+0x2831/0x3000 arch/x86/include/generated/asm/syscalls_64.h:20\n  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n  do_syscall_64+0xd8/0x2c0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nvalue changed: 0x00000000 -\u003e 0x00000001","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":"mISDN: annotate data-race around dev-\u003ework","id":"CVE-2026-23121","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"race_condition","year":"2026"},"n_packages":0,"n_references":7,"next":{"headline":"igc: Reduce TSN TX packet buffer from 7KB to 5KB per queue","id":"CVE-2026-23122"},"packages":[],"prev":{"headline":"l2tp: avoid one data-race in l2tp_tunnel_del_work()","id":"CVE-2026-23120"},"products":["Linux"],"published":"2026-02-14","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-10-19","vendors":["Linux"]},"summary":"A data race in the Linux kernel mISDN driver can lead to undefined behavior, requiring kernel patching to ensure thread safety.","url":"https://insights.sbomify.com/CVE-2026-23121/"}