{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-63896 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-63896 is a vulnerability in Linux, published on 19 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link."},"fix_prompt":"Check this codebase for CVE-2026-63896 and fix it if it is affected.\n\nWhat it is: CVE-2026-63896 is a vulnerability in Linux, published on 19 Jul 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.\nExploitation: There is no known exploitation of CVE-2026-63896 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-2026-63896/ (Markdown: https://insights.sbomify.com/CVE-2026-63896/index.md)","id":"CVE-2026-63896","markdown":"https://insights.sbomify.com/CVE-2026-63896/index.md","name":"CVE-2026-63896","record":{"aliases":["BELL-CVE-2026-63896","DEBIAN-CVE-2026-63896","GHSA-5hvq-fg66-prgg","UBUNTU-CVE-2026-63896"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service","data_read"],"network_reachable":"adjacent_or_local","non_default_config":true,"product_category":"Linux kernel USB gadget","requires_auth":"none","summary":"A malicious USB host can trigger an integer underflow in the Linux kernel WebUSB handler, causing a large out-of-bounds memory copy and potential system crash or information leak.","user_interaction":"required","vuln_class":"integer_overflow"},"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\nusb: gadget: composite: fix integer underflow in WebUSB GET_URL handling\n\nThe WebUSB GET_URL handler in composite_setup() narrows\nlanding_page_length to fit the host-supplied wLength using\n\n\tlanding_page_length = w_length\n\t\t- WEBUSB_URL_DESCRIPTOR_HEADER_LENGTH + landing_page_offset;\n\nIf wLength is smaller than WEBUSB_URL_DESCRIPTOR_HEADER_LENGTH the\nunsigned subtraction wraps, and the subsequent\n\n\tmemcpy(url_descriptor-\u003eURL,\n\t       cdev-\u003elanding_page + landing_page_offset,\n\t       landing_page_length - landing_page_offset);\n\nends up copying close to UINT_MAX bytes from cdev-\u003elanding_page into\ncdev-\u003ereq-\u003ebuf.  KASAN reports a slab-out-of-bounds in composite_setup\non the kmalloc-2k gadget_info allocation, and FORTIFY_SOURCE traps the\nmemcpy as a 4294967293-byte field-spanning write into\nurl_descriptor-\u003eURL (size 252).\n\nA USB host can reach this from a single SETUP packet against any\ngadget that has webusb/use=1 and a landingPage configured.\n\nHandle the small-wLength case before the math: when the host requested\nfewer bytes than the URL descriptor header, only the header is\nmeaningful and no URL bytes need to be copied.  Setting\nlanding_page_length to landing_page_offset makes the existing memcpy a\nno-op and leaves the descriptor returned to the host unchanged for all\nlarger wLength values.","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: composite: fix integer underflow in WebUSB GET_URL handling","id":"CVE-2026-63896","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"integer_overflow","year":"2026"},"n_packages":0,"n_references":5,"next":{"headline":"USB: serial: mct_u232: fix missing interrupt-in transfer sanity check","id":"CVE-2026-63897"},"packages":[],"prev":{"headline":"usb: gadget: f_fs: copy only received bytes on short ep0 read","id":"CVE-2026-63895"},"products":["Linux"],"published":"2026-07-19","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":"2026-07-19","vendors":["Linux"]},"summary":"A malicious USB host can trigger an integer underflow in the Linux kernel WebUSB handler, causing a large out-of-bounds memory copy and potential system crash or information leak.","url":"https://insights.sbomify.com/CVE-2026-63896/"}