{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-31726 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-31726 is a medium-severity vulnerability in Linux kernel, published on 1 May 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-2026-31726 and fix it if it is affected.\n\nWhat it is: CVE-2026-31726 is a medium-severity vulnerability in Linux kernel, published on 1 May 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-2026-31726 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-2026-31726/ (Markdown: https://insights.sbomify.com/CVE-2026-31726/index.md)","id":"CVE-2026-31726","markdown":"https://insights.sbomify.com/CVE-2026-31726/index.md","name":"CVE-2026-31726","record":{"aliases":["BELL-CVE-2026-31726","DEBIAN-CVE-2026-31726","GHSA-m9p5-m8gg-jgg8","ROOT-OS-DEBIAN-11-CVE-2026-31726","ROOT-OS-UBUNTU-2204-CVE-2026-31726","ROOT-OS-UBUNTU-2404-CVE-2026-31726","UBUNTU-CVE-2026-31726"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel USB gadget","requires_auth":"low_privilege","summary":"A race condition during USB gadget unbind causes a NULL pointer dereference, leading to a kernel panic and denial of service.","user_interaction":"not_required","vuln_class":"null_dereference"},"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-476","name":"NULL Pointer Dereference"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: uvc: fix NULL pointer dereference during unbind race\n\nCommit b81ac4395bbe (\"usb: gadget: uvc: allow for application to cleanly\nshutdown\") introduced two stages of synchronization waits totaling 1500ms\nin uvc_function_unbind() to prevent several types of kernel panics.\nHowever, this timing-based approach is insufficient during power\nmanagement (PM) transitions.\n\nWhen the PM subsystem starts freezing user space processes, the\nwait_event_interruptible_timeout() is aborted early, which allows the\nunbind thread to proceed and nullify the gadget pointer\n(cdev-\u003egadget = NULL):\n\n[  814.123447][  T947] configfs-gadget.g1 gadget.0: uvc: uvc_function_unbind()\n[  814.178583][ T3173] PM: suspend entry (deep)\n[  814.192487][ T3173] Freezing user space processes\n[  814.197668][  T947] configfs-gadget.g1 gadget.0: uvc: uvc_function_unbind no clean disconnect, wait for release\n\nWhen the PM subsystem resumes or aborts the suspend and tasks are\nrestarted, the V4L2 release path is executed and attempts to access the\nalready nullified gadget pointer, triggering a kernel panic:\n\n[  814.292597][    C0] PM: pm_system_irq_wakeup: 479 triggered dhdpcie_host_wake\n[  814.386727][ T3173] Restarting tasks ...\n[  814.403522][ T4558] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000030\n[  814.404021][ T4558] pc : usb_gadget_deactivate+0x14/0xf4\n[  814.404031][ T4558] lr : usb_function_deactivate+0x54/0x94\n[  814.404078][ T4558] Call trace:\n[  814.404080][ T4558]  usb_gadget_deactivate+0x14/0xf4\n[  814.404083][ T4558]  usb_function_deactivate+0x54/0x94\n[  814.404087][ T4558]  uvc_function_disconnect+0x1c/0x5c\n[  814.404092][ T4558]  uvc_v4l2_release+0x44/0xac\n[  814.404095][ T4558]  v4l2_release+0xcc/0x130\n\nAddress the race condition and NULL pointer dereference by:\n\n1. State Synchronization (flag + mutex)\nIntroduce a 'func_unbound' flag in struct uvc_device. This allows\nuvc_function_disconnect() to safely skip accessing the nullified\ncdev-\u003egadget pointer. As suggested by Alan Stern, this flag is protected\nby a new mutex (uvc-\u003elock) to ensure proper memory ordering and prevent\ninstruction reordering or speculative loads. This mutex is also used to\nprotect 'func_connected' for consistent state management.\n\n2. Explicit Synchronization (completion)\nUse a completion to synchronize uvc_function_unbind() with the\nuvc_vdev_release() callback. This prevents Use-After-Free (UAF) by\nensuring struct uvc_device is freed after all video device resources\nare released.","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":"usb: gadget: uvc: fix NULL pointer dereference during unbind race","id":"CVE-2026-31726","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"null_dereference","year":"2026"},"n_packages":0,"n_references":8,"next":{"headline":"usb: gadget: u_ether: Fix NULL pointer deref in eth_get_drvinfo","id":"CVE-2026-31727"},"packages":[],"prev":{"headline":"usb: gadget: f_ecm: Fix net_device lifecycle with device_move","id":"CVE-2026-31725"},"products":["Linux"],"published":"2026-05-01","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":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-05-23","vendors":["Linux"]},"summary":"A race condition during USB gadget unbind causes a NULL pointer dereference, leading to a kernel panic and denial of service.","url":"https://insights.sbomify.com/CVE-2026-31726/"}