{"cve":"CVE-2026-63960","nvd":{"published":"2026-07-19T16:17:14.897","modified":"2026-10-30T14:31:22.270","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nusb: typec: wcove: don't write past struct pd_message in wcove_read_rx_buffer()\n\nwcove_read_rx_buffer() copies the PD RX FIFO into the caller's\nstruct pd_message with\n\n\tfor (i = 0; i < USBC_RXINFO_RXBYTES(info); i++)\n\t\tregmap_read(wcove->regmap, USBC_RX_DATA + i, msg + i);\n\nwhich has two problems:\n\nUSBC_RXINFO_RXBYTES() is a 5-bit field (max 31) while struct pd_message\nis 30 bytes (__le16 header + __le32 payload[PD_MAX_PAYLOAD], packed).\nThe byte count latched in RXINFO is the number of bytes the port partner\nput on the wire, so a malicious partner that transmits a 31-byte frame\ncan drive the loop one byte past the destination if the WCOVE BMC\nreceiver does not enforce the PD object-count limit in hardware. The\nexisting FIXME flagged this as unverified.\n\nIndependently, regmap_read() takes an unsigned int * and stores a full\nunsigned int at the destination. Passing the byte pointer msg + i means\neach iteration writes four bytes; the high three are zero (val_bits is\n8) and are normally overwritten by the next iteration, but the final\niteration's high bytes are not. With RXBYTES == 30 the i == 29 iteration\nalready writes three zero bytes past msg, which sits on the IRQ thread's\nstack in wcove_typec_irq().\n\nClamp the loop to sizeof(struct pd_message) and read each register into\na local before storing only its low byte, so the copy can never exceed\nthe destination regardless of what RXINFO reports.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/3e632098d0521257ea965bbd6fde807d9bee5c8a","https://git.kernel.org/stable/c/3f9d50c8b02b4af0646aa892465080f9061fc89c","https://git.kernel.org/stable/c/4af7ad0e6d7aa4403dbb1dac7b9659b0421efcaa","https://git.kernel.org/stable/c/5cd0e7ac4eefbdb330f8c72694fe74e63df65552","https://git.kernel.org/stable/c/6899f5b6d7b83ce79a3d331dc61dd31bf73f9c22"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-30T14:49:48.263840089+00:00"},"epss":{"cve":"CVE-2026-63960","score":0.00211,"percentile":0.11342,"date":"2026-10-30"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}