CVE-2026-74557
HighCVSS 7.5Exploitation Probability (EPSS)
Low risk22th percentile - higher than 22% of all known CVEs
Summary
In the Linux kernel's libiscsi (SCSI) library, there is a vulnerability involving stale-data leak into the sense buffer. The iscsi_scsi_cmd_rsp() function copies sense data from a SCSI response, but the bounds check does not account for the 2-byte sense length prefix. A target can return a response with datalen equal to senselen, causing a read up to two bytes past the data and copying them into the sense buffer, which is returned to userspace.
Risk Assessment
The vulnerability could allow an attacker controlling an iSCSI target to leak stale kernel memory to userspace, potentially exposing sensitive information. It could also lead to a system crash due to improper memory access.
Recommendation
It is recommended to update the Linux kernel to a version containing the fix that accounts for the 2-byte sense length prefix in the bounds check. Also, limit trust in iSCSI targets and monitor traffic.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: scsi: libiscsi: Fix stale-data leak into the SCSI sense buffer iscsi_scsi_cmd_rsp() copies the sense data of a SCSI Response from the target-supplied data segment. The segment carries a 2-byte sense length followed by the sense bytes, so it must hold 2 + senselen bytes, but the bounds check only requires datalen >= senselen: senselen = get_unaligned_be16(data); if (datalen < senselen) goto invalid_datalen; memcpy(sc->sense_buffer, data + 2, min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE)); A target that returns a SCSI Response whose datalen equals senselen (with senselen <= SCSI_SENSE_BUFFERSIZE) makes the memcpy() from data + 2 read up to two bytes past the received data. Those bytes are stale conn->data contents and end up in the command's sense buffer, which is returned to userspace. Account for the 2-byte sense length prefix in the check.