{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-64339 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-64339 is a high-severity vulnerability in Linux kernel, published on 25 Jul 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-2026-64339 and fix it if it is affected.\n\nWhat it is: CVE-2026-64339 is a high-severity vulnerability in Linux kernel, published on 25 Jul 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-2026-64339 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-2026-64339/ (Markdown: https://insights.sbomify.com/CVE-2026-64339/index.md)","id":"CVE-2026-64339","markdown":"https://insights.sbomify.com/CVE-2026-64339/index.md","name":"CVE-2026-64339","record":{"aliases":["BELL-CVE-2026-64339","DEBIAN-CVE-2026-64339","GHSA-m28f-fmgf-v7cw","ROOT-OS-UBUNTU-2204-CVE-2026-64339","UBUNTU-CVE-2026-64339"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["data_read"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel USB driver","requires_auth":"low_privilege","summary":"A malicious USB device can trigger an out-of-bounds read in the Linux kernel usbio driver, leaking adjacent slab memory to user space.","user_interaction":"not_required","vuln_class":"information_disclosure"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":7.1,"severity":"high","source":"nvd","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-125","name":"Out-of-bounds Read"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: misc: usbio: bound bulk IN response length to the received transfer\n\nusbio_bulk_msg() copies bpkt_len = le16_to_cpu(bpkt-\u003elen) bytes out of\nthe bulk IN buffer (usbio-\u003erxbuf, allocated with size usbio-\u003erxbuf_len)\ninto the caller's buffer.  bpkt_len is fully controlled by the device\nand is only checked against ibuf_len; ibuf_len in turn is checked\nagainst usbio-\u003etxbuf_len, not against rxbuf_len:\n\n\tif ((obuf_len \u003e (usbio-\u003etxbuf_len - sizeof(*bpkt))) ||\n\t    (ibuf_len \u003e (usbio-\u003etxbuf_len - sizeof(*bpkt))))\n\t\treturn -EMSGSIZE;\n\ntxbuf_len and rxbuf_len are taken independently from the bulk OUT and\nbulk IN endpoint wMaxPacketSize in usbio_probe().  A malicious or\nmalfunctioning device that advertises a large bulk OUT endpoint and a\nsmall bulk IN endpoint (e.g. by claiming one of the quirk-free IDs such\nas the Lattice NX33U, 0x2ac1:0x20cb) therefore makes ibuf_len, and\nhence the device-supplied bpkt_len, exceed rxbuf_len.  memcpy() then\nreads up to txbuf_len - rxbuf_len bytes past the end of the rxbuf slab\nobject.  The over-read bytes are handed back to the i2c layer and on to\nuser space through i2c-dev, disclosing adjacent slab memory; with KASAN\nthis is reported as a slab-out-of-bounds read.\n\nThe number of bytes actually received is already known: act equals the\nURB actual_length and is bounded by rxbuf_len.  Reject any response\nthat claims more payload than was received, mirroring the existing\n\"act \u003c sizeof(*bpkt)\" check just above.\n\nThe control path (usbio_ctrl_msg()) is not affected: it uses a single\nbuffer (ctrlbuf) for both directions, so its analogous copy can never\nleave the allocation.\n\nFound by code review.  The out-of-bounds read was confirmed under\nAddressSanitizer with a faithful userspace model of usbio_bulk_msg()'s\nreceive path (an rxbuf_len-sized buffer, the same act/ibuf_len/bpkt_len\nchecks and the memcpy).  A USB raw-gadget + dummy_hcd reproducer is\nalso available.","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: misc: usbio: bound bulk IN response length to the received transfer","id":"CVE-2026-64339","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"information_disclosure","year":"2026"},"n_packages":0,"n_references":3,"next":{"headline":"USB: legousbtower: fix use-after-free on disconnect race","id":"CVE-2026-64340"},"packages":[],"prev":{"headline":"USB: misc: uss720: unregister parport on probe failure","id":"CVE-2026-64338"},"products":["Linux"],"published":"2026-07-25","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":"2026-08-17","vendors":["Linux"]},"summary":"A malicious USB device can trigger an out-of-bounds read in the Linux kernel usbio driver, leaking adjacent slab memory to user space.","url":"https://insights.sbomify.com/CVE-2026-64339/"}