CVE-2026-74507
HighCVSS 7.1Exploitation Probability (EPSS)
Low risk14th percentile - higher than 14% of all known CVEs
Summary
In the Linux kernel, in the Bluetooth HIDP subsystem, a vulnerability was found where numbered report payloads are not validated. When hidp_get_raw_report() waits for a numbered report, hidp_process_data() compares the expected report number with skb->data[0]. A connected HIDP peer can reply with only a DATA transaction header, leaving the skb empty after the header is removed. The fix requires a payload byte before comparing a numbered report ID; unnumbered reports continue to accept an empty payload.
Risk Assessment
The vulnerability may lead to use of uninitialized memory or acceptance of malicious responses, which could be exploited for DoS or data integrity compromise.
Recommendation
Apply a Linux kernel update containing the fix for CVE-2026-74507. Restrict Bluetooth access for untrusted devices.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: HIDP: validate numbered report payloads When hidp_get_raw_report() waits for a numbered report, hidp_process_data() compares the expected report number with skb->data[0]. A connected HIDP peer can reply with only a DATA transaction header, leaving the skb empty after the header is removed. KMSAN reports an uninitialized-value use in hidp_session_run(), with the value originating in __alloc_skb() through vhci_write(). The transaction header checks remove the empty-frame reports, but this report remains until the payload check is added. The comparison can also consume a peer-controlled byte beyond the declared L2CAP PDU. A DATA | FEATURE response followed by an extra 0x01 byte made the current code accept that byte as report ID 1 and complete HIDIOCGFEATURE with a zero-byte result. With this change the malformed response is rejected with -EIO, while a subsequent valid response still succeeds. Require a payload byte before comparing a numbered report ID. Unnumbered reports continue to accept an empty payload.